Abstract: Objective To understand the trend of HIV/AIDS knowledge, risk behaviors and HIV/AIDS prevalence among peasant-workers. Methods Fixed location continuous sampling method was used. Questionnaire survey and HIV antibody test were carried out among peasant-workers from 2012 to 2014 in Dali city. Sample size was 400 per year. Results The rate of HIV/AIDS knowledge for peasant-workers increased from 79.8% to 98.5%(χ²=80.17,P<0.001). Multivariate analysis showed that education level, whether received AIDS intervention services and age were independent factors for AIDS knowledge. There was no trend change about the rate of consistent condom use with sex workers in 2012-2014(r=-0.238,P=0.149). The rate of consistent condom use with casual sexual partners were 28.6%,46.4% and 56.3%, respectively. The rate of consistent condom use with spouses increased slightly from 4.8% to 6.3%(r=0.048,P=0.031). From 2012 to 2014, HIV prevalence rate was 0.0%, 0.0% and 0.5%, respectively. Conclusions Behavior intervention among peasant-workers has made some progress, but the rate of condom use is not satisfactory. Special attention should be paid to the increasing trend of casual sex behavior. Further effort should be focused on multi-sector cooperation, increasing coverage of comprehensive intervention and HIV testing service, especially among older and lower education background peasant-workers.