One study of computing schools found that only 10 percent of teachers had actually worked in the sector. And too often, their critics say, the courses and teaching methods vocational schools offer are out of step with the demands of the economy.

Yu Zhongwen, former head of two vocational schools and the vice-chairman of the Chinese Society of Vocational and Technical Education, blames a historic lack of government funding compared with the subsidies for traditional education and insufficient corporate involvement in the vocational education system.

The Ministry of Education declined a request for comment, saying only that "relevant documents were still being researched and drafted".

In a rural area of Guiyang, the capital city of Guizhou province, tree-covered hills are being razed to make room for the Qingzhen Vocational Education City.

Seventeen schools have already agreed to be part of the zone, including agricultural engineering, transportation, construction and automotive schools. The zone has capacity for 35 schools and 300,000 students.

At the Guizhou Machinery Industry School, where enrolment is expected to increase from about 7,000 students this year to 10,000 next year, vice-president Xu Guoqing said that grouping schools together in a new district will help dispel parents' concerns about the quality of vocational education and lessen overlap in course offerings.

State subsidies sweeten the deal. All of the students at Guizhou Machinery are on full scholarships funded by the provincial government. Because they come from poor areas, more than 80 percent of students receive a 2,000 yuan ($315) annual living expenses stipend from the central government.

Students said they appreciated the schools' focus on practical skills, rather than the theory taught in conventional high school or university.

"Going to class feels like going to work in a factory," said Wu Wei, a student at the construction school.

Indeed, one of the criticisms of China's vocational schools is that rather than educating their students, some have simply shipped them off to work at factories as interns under conditions that violate Chinese labor law.

Guizhou Machinery Industry School's Xu said that what matters in vocational education is not how big a school is, but how it is run.

The stakes are rising for China's vocational schools. "If we run things the old way, we'll be left behind," Xu said.