This data article presents data from the China Migrants Dynamic Survey (CMDS), a multi-wave, large-scale national cross-sectional survey of China’s internal migrants from 2009 to 2018. The CMDS is an annual questionnaire survey conducted by the former National Health and Family Planning Commission (NHFPC) of the People’s Republic of China. The respondents included in this survey are internal migrants over 15 years old. The sample was drawn from the China Migrant Population Information System, using multi-stage stratified sampling method and the probability proportional-to-size (PPS) cluster sampling strategy. Between 2009 and 2018, there were 1,527,650 internal migrants from 23 provinces, 5 autonomous regions and 4 municipalities participated in the surveys. The survey tools were a series of self-designed questionnaires with high inheritance and consistency designed and implemented by the NHFPC. The questionnaires mainly contain basic information of the respondents and their family members, migration status, healthcare or health behaviors, public health service utilization, social insurance, social integration, and family planning. The dataset is currently the most widely used survey data on China’s internal migrants, offering information on migration patterns, healthcare and health behaviors, use of public health services, access to social security, social integration, and family planning, which are valuable for health planning, health decision-making, and health equity research.

Key words: internal migrants, healthcare and health services, family planning, dynamic monitoring, China Migrants Dynamic Survey (CMDS)