Regulations of the People’s republic of China on Administration of the Entry and Exit of Foreigners
Article 22 Where a foreigner holding a residence permit for study intends to engage in off-campus work-study or internship, he or she shall, upon the approval of the school, apply to the exit and entry administration authority of the public security organ to have such information as the location and duration of the work-study program or internship placement specified in his or her residence permit.
A foreigner holding a residence permit for study shall not engage in any off-campus work-study or internship unless the information prescribed in the preceding paragraph is specified in his or her residence permit.
Exit and Entry Administration Law of the People’s Republic of China
Article 42 The competent department of human resources and social security and the competent department in charge of foreign experts affairs under the State Council shall, in conjunction with relevant departments under the State Council, formulate and regularly adjust the guiding catalogue for foreigners working in China based on the needs for economic and social development as well as the supply and demand of human resources.
The competent department of education under the State Council shall, in conjunction with relevant departments under the State Council, establish an administrative system for foreign students working to support their study in China and set forth regulations on the scope of jobs and the limit of work time for such foreign students.
Article 43 Any of the following acts of foreigners shall be deemed unlawful employment:
(1) Work in China without obtaining work permits or work-type residence permits in accordance with relevant regulations;
(2) Work in China beyond the scope prescribed in the work permits; or
(3) Foreign students work in violation of the regulations on the administration of foreign students working to support their study in China and work beyond the prescribed scope of jobs or prescribed time limit.
More detailed information can be found from these two websites:
http://cs.mfa.gov.cn/zlbg/flfg/crjxg/t1060665.shtml
http://cs.mfa.gov.cn/zlbg/flfg/crjxg/t1054650.shtml