Purposes : To investigate income mobility of farm households with land-expropriated in the process of urbanization in China, and explore factors affecting income mobility. Methods: Data derives from a project financially supported by Natural Science Foundation of China in 2013. Using principles of stratified random sampling, 429 farm households are selected. Data: income; endowments; demographic; schemes in supporting land expropriation; risk factors. We use Income Transition Matrix to investigate income mobility, and Ordinal Logistic Regression to explore its determinants. Conclusions: 1) Income mobility has different changing patterns after land expropriation. 2) Working capitals, including land, level of labor force s education and social relations, are linked to income mobility changes. Capital accumulation is important. 3) Households in lower/medium income groups are more likely to flow downward when they have: lower level of education, or weak social capital, or larger land expropriation, or member suffering health risk, or not participate in government "Land for Social Security" scheme. 4) Types of risk are closely associated with income downward flow. Interventions should target at strengthening household working capitals, especially human capital, and at preventing them from suffering risks, and at reforming "Land for Social Security" scheme to support sustainable livelihoods. Key words: Income Mobility, Land expropriation, Farm Households, Capitals, Risks Acknowledgement : Funding for data collection has been provided by the National Natural Science Foundation of China (grant number:71173239). We thank Dr Wu Haitao for valuable comments.