Abstract: Objective To understand the prevalence of human immunodeficiency virus (HIV) and syphilis infection and their associated factors among men who have sex with men (MSM) in Jiangsu Province. Methods MSM from eight cities in Jiangsu Province were recruited for questionnaire interview and laboratory test in 2015. Multivariate Logistic regression model was used to analyze associated factors of HIV and syphilis infection. Results The prevalence of HIV and syphilis were 10.3% and 8.3% among 2 451 MSM, respectively. MSM who were older than 40 years were recruited via internet, engaged in unprotected anal intercourse (UAI) in the past 6 months, did not have an HIV test in the past year and were currently infected with syphilis were susceptible to HIV infection (all P<0.05). MSM who were older than 24 years, had an education level of junior high school or less were recruited in venues and engaged in UAI in the past 6 months were susceptible to syphilis infection(all P<0.05). Conclusions Continuous high HIV prevalence and controlled syphilis epidemic were shown among MSM in Jiangsu Province. Condom usage and HIV/syphilis testing promotion should be prioritized when attempting to reduce HIV/syphilis transmission among MSM in Jiangsu Province.