Instead of focusing on their own research work, Chinese students enrolling in PhD programs are now becoming cheap labor of their professors, whom they often call "bosses", according to China Youth Daily`s report Tuesday.

A total of 60 percent doctoral students said they do more than half of the tasks which should be the responsibility of their professors. And some even give the entire research work to their students, according to recent survey, which interviewed 1,392 PhD candidates, degree holders, professors and employers.

By working for their bosses` projects, the students usually are paid a certain amount of money, which pales in comparison with what they can earn by working for a private company.

"I have taken part in many projects here and done a lot of business travel, what is the difference between this and a fulltime job?" an interviewee of the survey said, adding the current mentor-student relationship has become an employment relationship and the students` academic skills are not really improving.

Wu Gang, a doctoral student at a university in Beijing who is about to graduate, said he is pondering whether or not to turn off his cell phone during the new semester, because he doesn`t want to get calls from his professor giving him tasks unrelated to his research.

But doing this will definitely block potential job opportunities, a risk that can`t be taken by a student such as Wu, who is looking for a fulltime job.

Wu is not alone. Some doctoral students even blacklist their professors` phone numbers on their cell phones, according to the survey.

Wu has helped his professor do many chores that have nothing to do with his research, including delivering fruits to some other professors.

Zhao Pu, a doctoral degree holder who graduated from an engineering university in Wuhan in Central China`s Hubei province, said many professors will get projects from some companies and then form a team consisting of the professors` doctoral students and postgraduate students to complete the projects. The students will get paid in accordance with their contributions to the projects.

"Most engineering doctoral students have had the experience of working for their bosses` private businesses," Zhao said. "If you are found by your boss to be a good worker, your graduation may be postponed."

Zhao said he is quite lucky to "flee" and graduate on time.

Working on some projects for professor leads many doctoral degree students to believe they can perform well in their jobs. But about 70 percent of employers in the survey complained that employees who hold PhDs show little innovation in their work performance.

China replaced the United States to become the world`s top producer of doctorate holders in 2008. The number of PhD students in China reached 246,300 in 2009, about five times the figure in 1999.

But the massive enrolment of doctoral students has resulted in a severe shortage of qualified professors and posed a great challenge to the current education system, according to Zhou Guangli, a professor at the Institute of Education Sciences in Huazhong University of Science and Technology who was in charge of the survey.

In the current doctoral education system, professors don`t take responsibility for their students’ ability and those unqualified don`t have the pressure of being laid off, which make the professors believe doing a good or a bad job makes no difference, according to Zhou.