Objective:To investigate the incidence and correlates of HIV-1 drug resistance among men who have sex with men(MSM)on highly active antiretroviral therapy (HAART). Methods:We conducted a prospective cohort study in Jiangsu province to estimate the incidence of HIV-1 drug resistance (HDR). Cox regression model was used to investigate the correlations of HDR. Results:During the follow-up period,23 MSM acquired drug resistance,and the incidence was 2.72 per 100 person-years. The independent risk factors of HDR were the CD4+T cell count (less than 200 copies/μl)before ART (HR:3.210;95%CI:1.333~7.733),and the use of nevirapine(NVP)on initial regimen (HR:2.852;95%CI:1.194~6.817). Conclusion:The incidence of HDR among MSM on ART was low. Early treatment of MSM infected with HIV-1 was recommended according to our study. It’s better to use EFV rather than NVP when initiate ART.