In China, temporary migration is defined as a change in place of residence without a concomitant change in household registration; such mobility therefore encompasses a more heterogeneous set of movements than is usually subsumed under this heading in other nations. Because of China’s strict control of permanent migration to large cities, temporary migration has become an important strategy for adjusting to economic changes and to effecting family reunification. The Shanghai Temporary Migration Survey of 1984 focused on one segment of temporary migrants, the 58% living in the households of permanent residents. Multinomial logistic regression suggests the heightened probability that close relatives of the household heads come to Shanghai to visit or to live, and nonrelatives to work. Regression on current and expected duration shows that many intended to stay for a year or more, some for up to 20 years. Their presence in the city places added strains on infrastructure and raises questions about the continued efficacy of China’s migration policies.