Ladies and gentlemen, thank you for standing by, and welcome to Sunlands' Second Quarter 2020 Earnings Conference Call. At this time, all participants are in a listen-only mode. After prepared remarks by the management team, there will be a question-and-answer session. Today's conference call is being recorded. If you have any objections, you may disconnect at this time. I would now like to turn the call over to your host today, Yuhua Ye, Sunlands IR Representative. Please go ahead.
Hello, everyone, thank you for joining Sunlands' Second Quarter 2020 Earnings Conference Call. The company's financial and operating results were issued in a press release via Newswire services earlier today and are posted online. You can download the earnings press release and sign up for our distribution list by visiting our IR website. On the call, our CEO, Tongbo Liu, will provide an update on our operational performance as well as our strategic initiatives. Our CFO, Selena Lu Lv, will give you an overview of our financial performance and also provide our guidance for the second quarter of 2020. Following their prepared remarks, we will move into the Q&A session. Before I hand it over to the management, I would like to remind you of Sunlands' safe harbor statement in relation to today's call.
Except for the historical information contained herein, certain of the matters discussed in this conference call are forward-looking statements. These statements are based on current trends, estimates, and projections, and therefore you should not place undue reliance on them. Forward-looking statements involve inherent risks and uncertainties. A number of important factors could cause actual results to differ materially from those contained in any forward-looking statement. For more information about potential risks and uncertainties, please refer to the company's filings with the Securities and Exchange Commission. With that, I will now turn the call over to our CEO, Tongbo Liu.
Thank you, Yuhua. Hello, everyone. Welcome to Sunlands' second quarter 2020 conference call. With the COVID-19 pandemic in China was effectively contained during the second quarter, due to the varying work resumption requirements in different regions, the average resumption rate of our Wuhan campus and the headquarters in Beijing was about 18%. Against this backdrop, we are pleased with maintaining steady growth in the second quarter. Thanks to our self-developed collaborative online office system, efficient operation management, and rigorous execution, we achieved satisfactory financial results for this quarter. Our net revenues reached CNY 512.5 million, in line with our guidance. Additionally, we are proud to say that our more than 8,000 employees in four cities are all safe and sound. Our gross billing achieved year-over-year growth for the first time in five quarters, increasing by 21.3% to CNY 531.5 million compared with the prior year period.
In addition, new student enrollments increased by 10.2% year-over-year. The increases were mainly driven by our strategy to diversify product and service offerings, continuous expansion in training course categories, improve the efficiency of our sales team, as well as tremendous efforts from all of our employees. Next, let me provide highlights at the business segment level. Our business mainly focuses on three categories, STE, master's degree-oriented programs, and professional certification and skills programs. Our STE programs have maintained a solid market position and market share, and master's degree-oriented programs have become our strong new growth driver. According to the Ministry of Education, the number of applicants for postgraduate programs are expected to reach a record high of 3.41 million, representing an increase of 510,000 or 17.6% year-over-year from 2.9 million in 2019.
In response to the strong growth of applicants, the Ministry of Education made an announcement in February to expand the number of admissions in 2020 by 189,000 from last year's level. The ever-expanding number of people taking the postgraduate admission test comes from the rising pressure of employment in China and increasing demand for talents with higher education from enterprises. According to China Education Online, former students, mostly working professionals, accounted for 45% of those taking the postgraduate admission test in 2018. Leveraging our student acquisition experience and service advantages for this group of people, we focused on providing the postgraduate admission test preparation for working professionals and have achieved remarkable results. Our master's degree-oriented programs have grown year-over-year for eight consecutive quarters.
Gross billings of master's degree-oriented programs for this quarter reached a new high of CNY 135.2 million, up 158.7% year-over-year and accounting for 25.4% of total gross billing. This proportion was significantly higher than 2019 and 2018, during which our master's degree-oriented programs accounted for only 17.9% and 5.5% of gross billings respectively. At the same time, based on student demands and the new market trends, Sunlands is also actively expanding our course offerings in multiple categories, including professional certifications and the trainings related to new occupations, as well as new skills and hobbies training, catering to persons' diverse interests. The segment reached CNY 59.5 million in gross billing this quarter, up 58.4% year-over-year, accounting for 11.2% of total, compared with 6.9% in 2019. We expect continued robust growth for this segment, as its ASP is relatively low at approximately CNY 3,000.
We are in the process of adding more courses for our new and existing students to experience on our live streaming or live teaching platform. We are pleased to say that as these new categories of courses are much shorter than degree courses, students are stickier and have a higher repurchase rate, which we expect to contribute positively to our profitability improvement. In the future, we will continue to take advantage of STG platform and our teachers' rich teaching experience, constantly develop more online short-term courses suitable for adults, in order to expand our target user base and promote course selling. Lastly, due to the postponement of the national STE exams from April to August, gross billings of STE programs, our largest segment, also increased by 6.8% year-over-year in the second quarter, as both new student enrollments and ASP increased.
In the second quarter, our students, including those taking trial and free classes, showed greater enthusiasm to study during the pandemic period, as we continuously optimize our three-teacher system. This system refers to our comprehensive solution that combines live streaming lectures, after-class mentors, and AI-powered personal tutors. In this quarter, total time spent on online classes on our learning platform was 22.3 million hours, increasing 16.4% year-over-year and 25% quarter-over-quarter. The total number of online class attendees reached 758,000, and the average time spent this quarter for each student was almost 30 hours. An interesting fact was that of the total time spent on live streaming classes during this quarter, nearly 5.5 million hours or about 24.5% were driven by students spending time on pre-sale trial or free courses, including various new courses and mini tutorials.
This was eight times higher compared to the level in the same period last year, and the same time higher versus last quarter. In addition, trial class students accounted for 27% of total students attending classes this quarter. Through the trial program, we enable prospective students to experience our course content and the teaching services in advance, which not only improves the retention rate of new students and expand our potential user pool, but also helps us develop a deeper understanding of student interests and realize additional course sale potentials.
Looking forward, we are confident to maintain the market-leading position of our existing service categories and continuously improve the learning effectiveness of our students through technical and operational advancement. We are also optimistic of the market opportunities and the possibilities of course selling as we develop new content and execute our efficient students acquisition strategy. With that, I would like to hand over the call to our CFO, Selena, to run through our financials.
Thank you, Tongbo, and hello, everyone. During the second quarter, our net revenues declined 7.3% year-over-year due to the decrease of gross billings last year. We are pleased that even against the backdrop of pandemic and a severe macroeconomic environment, our gross billings achieved a more than 20% year-over-year growth, reaching an important inflection point, and giving us confidence in its continuous growth in the future. We also noticed a greater change in the product mix of our gross billings. The proportions of master degree-oriented programs and professional certification and skills programs with our total gross billings both further increased. Since the service periods of these two categories are much shorter compared with our STE offerings, their increasing proportions will accelerate our revenue recognition and reduce the time gap due to mismatch between revenue recognition over time and expenses booking upfront.
On the expense side, we continued our pursuit of cost structure optimization, achieving 33.9% and 33.6% reductions in administrative expenses and R&D expenses respectively, compared with the same period last year. Going forward, our focus remains on the diversification of our online courses and the improvement of our technology and operational capabilities. More product offerings translate to bigger addressable market for us and higher cost leverage as well as increasing repurchasing potential from our students. Whereas technological and operational improvements provides our students better experiences, which will further strengthen our brand image and reputation, and ultimately improve our referral rate. We will also continue diversifying our student acquisition strategy and upgrading our conversion model, all in the effort to further improve our sales conversion rate and efficiency and drive sustainable long-term growth. Let me walk you through some of the key financial results for the second quarter of 2020.
All comparisons are year-over-year, and all numbers are in CNY. In the second quarter of 2020, net revenues were CNY 512.5 million, decreased by 7.3% year-over-year, mainly due to the decrease of gross billings last year. Cost of revenues increased by 4.1% to CNY 99.6 million in the second quarter of 2020 from CNY 95.7 million in the second quarter of 2019, which was primarily due to an increase in expenses related to service fees to educational institutions. Gross profit decreased by 9.7% to CNY 412.9 million from CNY 457 million in the second quarter of 2019. In the second quarter of 2020, operating expenses were CNY 560 million, representing a 12.3% increase from CNY 498.7 million in the second quarter of 2019. Sales and marketing expenses increased by 25.2% to CNY 487.9 million in the second quarter of 2020 from CNY 389.7 million in the second quarter of 2019.
The increase was mainly due to increases in, number one, compensation paid to our sales and marketing personnel, and number two, spending on branding and marketing activities, including investments in broadening our diversified student acquisition channels. General and administrative expenses was CNY 56.1 million in the second quarter of 2020, decreased by 33.9% year-over-year, mainly due to the decrease in compensation expenses. Product development expenses decreased by 33.6% to CNY 16 million in the second quarter of 2020 from CNY 24 million in the second quarter of 2019. The decrease was primarily due to a decrease in the compensation incurred related to our product and technology development personnel during the quarter. Other income increased to CNY 17.5 million in the second quarter of 2020 from CNY 9 million in the second quarter of 2019.
The increase was primarily due to the value-added tax exemptions offered by the relevant authorities in the amount of CNY 15 million during the COVID-19 outbreak. Net loss for the second quarter of 2020 was CNY 126.1 million, compared with CNY 12.9 million in the second quarter of 2019. Basic and diluted net loss per share was CNY 18.7 in the second quarter of 2020. As of June 30th, 2020, the company had CNY 1,079.4 million of cash and cash equivalents and CNY 288.6 million of short-term investments. As of June 30th, 2020, the company had a deferred revenue balance of CNY 3,066 million, compared with CNY 3,228.8 million as of December 31st, 2019. Capital expenditures were incurred primarily in connection with IT infrastructure equipment and leasehold improvement necessary to support Sunlands operations.
Capital expenditure were CNY 1 million in the second quarter of 2020, compared with CNY 2.2 million in the second quarter of 2019. For the third quarter of 2020, Sunlands currently expects net revenues to be between CNY 500 million-CNY 520 million, which would represent a decrease of 5.2%-1.4% year-over-year. The above outlook is based on the current market conditions and reflects the company management's current and preliminary estimates of market operating conditions and customer demand, which are all subject to change. With that, I'd like to open up the call to questions. Operator?
Thank you. We will now begin the question-and-answer session. To ask a question, you may press star then one on your touchtone phone. If you are using a speakerphone, please pick up your handset before pressing the keys. To withdraw your question, please press star then two. For the benefit of all participants on today's call, if you wish to ask your question to management in Chinese, please immediately repeat your question in English. At this time, we will pause momentarily to assemble the roster. Showing no further questions, this will conclude our question-and-answer session. At this time, I'd like to turn the conference back over to management for any closing remarks.
Once again, thank you everyone for joining today's call. We look forward to speaking with you again soon. Good day and good night.
The conference is now concluded. Thank you for attending today's presentation. You may now disconnect.