SUMMARY:A cross sectional survey was performed to investigate the epidemic of human immunodeficiency virus (HIV), hepatitis C virus (HCV), syphilis, and HIV-1 subtype infections among men who have sex with men (MSM) and to evaluate factors that were correlated with sexually transmitted infections (STIs) among 657 MSM in Zhenjiang, Jiangsu, during 2012Jiangsu, during -2013. Data on socio-demographic parameters and risky behaviors were collected, and blood samples were obtained. In this survey, the prevalence of STIs due to HIV (5.3z), HCV (0.6z), and syphilis (19.2z) were measured. Of 35 HIVinfected MSM, 1 (0.2z) and 17 (2.6z) were co-infected with HCV and syphilis. Among 33 samples with available HIV-1 genomic fragment sequences, 6.1z B, 72.7z CRF01_AE, and 21.2z CRF07_ BC were identified. Multivariate logistic regression analysis showed that age > 30 years (odds ratio [OR] 2.002; 95z confidence interval [CI], 1.144-3.502) and having had STI symptoms in the past year (OR, 11.673; 95z CI, 3.092-44.078) were positively correlated with having an STI, while consistent use of a condom when having sex with male partners (OR, 0.621; 95z CI, 0.408-0.945) was significantly associated with a low STI rate. The worsening epidemic of HIV, HCV, and syphilis infections, and the prevalence of complex subtypes of HIV-1 and other risk factors suggest that effective intervention strategies should be strengthened for MSM in Zhenjiang, Jiangsu.