There are strict procedures for foreigners who wish to obtain visas to live and work in China. The most important visa classes for foreign workers are the Business/Official Visit Visa, the Employment/Work Visa, and the Resident Visa. There are other classes of visas for airline pilots, mariners, diplomats, tourists, family visits, students, and journalists.
Business and work permits must be obtained prior to entry into China, and numerous documents are required for a work visa application. If a foreigner works without the proper employment permit, public security officials are authorized to terminate the employment and impose a fine on the worker. In serious cases, the public security officials will force the expatriate to leave the country.
Keep in mind that the Chinese government does not recognize dual nationality and that visa requirements for Hong Kong are different than those for the People's Republic of China. Foreigners staying to work in China longer than one year must submit a notarized health certificate.