The following discussions come from a 2016 OECD report “EDUCATION IN CHINA: A Snapshot”[1].
In China, students usually enroll in pre-school at age two or three, and leave pre-school at the age of six. Pre-school education is not compulsory, and many pre-schools are privately owned. However, the government has taken on a more proactive role in promoting access following a national commitment to progressively universalize one to three years of pre-school by 2020.
In China, students must complete nine years of compulsory education. Most students spend six years in primary school, though a few school systems use a five-year cycle for primary school. Primary education starts at age six for most children. This is followed by three to four years of junior secondary education.
After finishing compulsory education, students can choose whether to continue with senior secondary education. Senior secondary education takes three years. There are five types of senior secondary schools in China: general senior secondary, technical or specialized secondary, adult secondary, vocational secondary and crafts schools. The last four are referred to as secondary vocational schools.
Although senior secondary education is not part of compulsory education in China, in 2014, 95% of junior secondary graduates continued their study in senior secondary schools (National Bureau of Statistics of China, 2015). This figure is notable because in 2005 only around 40% of junior secondary graduates attended senior secondary schools (National Bureau of Statistics of China, 2005).
[1] http://www.oecd.org/china/Education-in-China-a-snapshot.pdf