Abstract: ObjectiveTo study social support in transitional period among immigrants in Danjiangkou reservoir area. MethodsStratified multi-stage cluster sampling method was used in this study,a basic questionnaire and Social Support Rating Scale(SSRS)were used to investigate 392 quasi-migrants and 388 local residents in Xichuan county. ResultsThere were no significant differences in gender,age and annual household income between immigrants and local residents(P>0.05).Compared with local residents,the immigrants in transitional period had lower scores in objective support(18.79±4.01),subjective support(8.05±2.39),as well as SSRS total score(32.94±5.64),with statistically significant differences(P<0.05).The male immigrants obtained more subjective support(8.71±2.91)than female immigrants(8.50±2.64);the immigrants aged 30 to 59 years had more social support than those aged less than 30 years and 60 years or older.The imnigrants with higher education level had more social support. ConclusionThe immigrants during the transition period are different from local residents in mental health.The female,single,and farmer immigrants have lower social support.Attentions should be paid to mental health of the immigrants in transition periol.