Critics claim programs simply prep students for overseas education
Yang Dong is relieved to have escaped taking the gaokao, China's national college entrance exam.
Instead, he is preparing for a test that could land him a place at Cambridge University.
"I'm studying for the UK high school exam," said the 16-year-old, who hails from Chongqing and is enrolled in an international class in Shenzhen.
As opposed to international schools in China, which are for students with foreign passports and are fluent in English, international classes are run at public high schools for Chinese students.
They are designed to cater to the growing demand to study abroad; however, some critics argue they are merely preparatory schools for exams for overseas education systems.
"I want to study abroad because I want to avoid just practicing for one exam (gaokao), and I believe Western education systems value a students' self-improvement rather than grades," Yang said.
"If I still have to work hours on end to get a high score to enter a university in Britain, I'd rather spend quality time doing volunteer work." This, he believes, will place him in good stead in any overseas education program.
Many reputed public schools, such as the high schools attached to Renmin University of China and Tsinghua University in Beijing, as well as Tianjin Nankai High School and Chongqing No 1 Middle School, have established international classes and programs.
The recruitment standard is less restricted than for students looking to enter the main school.
For example, the minimum requirement for students applying to international classes at Chongqing No 1 Middle School is 50 points lower. Meanwhile, it charges 80,000 yuan ($13,400) for tuition, as much as a private school in the United States.
Some public high schools lack financial resources and have turned to international classes as a cash cow, which explains the high cost, said Yuan Guilin, a professor of education at Beijing Normal University.
Xiang Enhao studied at the international class at Chongqing No 1 but transferred after one semester.
"I was afraid I wasn't going to get into the best high schools after the Chinese entrance exam, so I thought studying abroad might be an option," he said.
However, Xiang said he discovered the class still involved learning gaokao subjects in Chinese, though with far less pressure.
He recalled a math teacher from the Philippines gave interesting lectures, but he added: "I thought I should have been under more pressure.
"Sometimes we watched movies during evening classes and rarely had any tests," he said, explaining his decision to quit.
Xiang is now a junior college student at a university in Chongqing. Talking about his goal of studying abroad, he was clearer about what he wants.
"I want to study electronic engineering in the US in graduate school, if my English is good enough," he said.
Zhang Han, executive vice-president of Quaker Education, a consultancy for overseas study, explained: "In today's market, international classes work in two ways: public school management or contract agents management. Self-management schools are better than contractors.
"However, no matter which school or programs the students come from, when universities recruit students, they value the quality of students themselves."
He said some students from normal public high schools behave better than the ones from international schools and classes.
Rahul Choudaha, director of research and strategic development at World Education Services, a New York nonprofit specializing in international education, sees "an increasing interest toward international classes catering specifically to the needs of students who want to study abroad".
He wrote in an e-mail to China Daiy that "it is a reflection of market demand where students and families are ready to not only invest early but also with more money with the hope of increasing their chances of success.
"In a way these classes are a glorified version of preparatory services offered by agents. Given that these initiatives are in their infancy, they have similar limitations over a lack of quality assurance and promising too much. These newer developments related to add-on ‘international classes' for overseas-bound students are different from reputed ‘international schools' like International Baccalaureate programs," he added.
Yang Dong enjoys his time in Shenzhen and spends his days and hours drawing.
"I know I want to become an architect; my school allows me the time and I feel closer to Cambridge," he said.
Ji Jin and Nie Yihemu contributed to this story.