In 1990, Japan opened a side-door to the international migration of low-skilled temporary workers. Subsequently, temporary migrants have increased in volume. They are considered trainees for the first year of their stay and only receive allowance. However, most of them actually do the same work as other workers. Many problems caused by this migration system have been reported.
　In this article, we focus on temporary migrants from China. How did they live in Chine before migrations? Why they migrant to Japan? What factor affects success or failure in their migrations?
　In 2010 and 2011, we carried out questionnaire surveys of 65 returnees from Japan. Results indicate that four migrants in five were female, 40 percent were married and one half had children. More than four respondents in five migrated because they desired to earn income, 38.5 percent migrated because they want to learn technical skills, 24.6 percent migrated because they want to see Japan. Most migrants are positive in their overall assessment of the impact of migration. Earnings and pre-departure costs are important factors affecting success or failure in their migrations. Results indicate that migrants who had children are more positive than the other in their overall assessment. Household in China is also important factor affecting migration.