The leagal term for a part-time job of college students from abroad is "activity other than that permitted by the status of residence previously granted". According to AIEJ research in 2001, over 76% of international students studying in Japan at private expenses engage in a part-time job. In this paper, I will mainly treat two big problems which some of those students may be involved in. One is non-payment of wages by an unprincipled employer, the other is deduction of income tax by both an innocent employer and a vicious employer. The former problem was caused by lasting deflation, and was acceralated by an outbreak of BSE in summer 2001 in Japan. The latter problem is typical for Chinese students because they are exempted from income tax under the tax treaty between Japan and China. I would also like to refer to the third problem, that is, a part-time job by students at the Japanese Government scholarship. These students have enough amount of money to spend without a part-time job.