Abstract: ObjectiveTo explore the characteristics of high-risk behaviors among men who have sex with men(MSM) in different venues and to provide evidence for human immunodificiency virus/sexually transmitted disease(HIV/STD)intervention.MethodsA total of 593 MSM(165 from bars,230 from public bathroom,198 from other places)were studied with a questionnaire interview and the information on health services,high risk behaviors were collected.Blood and urine samples were tested for HIV antibody,syphilis,Neisseria gonorrhoeae,and Chlamydia trachomatis.Results For the MSM from different venues,statistically significant differences were found in age,education background,marriage,living condition,occupation,and sex orientation(P<0.001).Compared to the MSM from other public places,the MSM from internet bar were significantly more likely to have sex with only men,with the rate of 48.7% (56/115)(χ²=50.376,P<0.001).The MSM from bars had the highest rate of commercial sex(20.2%,33/163).For the MSM from public bathroom,the rate of condom use in the last anal sex was significantly lower than those from other places(60.3%,91/151;χ²=11.147,P=0.004)and the rate of having sex with women in the last six months was significantly higher than those from other places (60.0%,138/230;χ²=35.883,P<0.001).The prevalence of HIV infection was 10.9% (18/165),16.1% (37/230), and 11.3% (13/115)and that of syphilis was 32.1% (53/165),37.4% (86/230),and 20.9% (24/115)for the MSM from bar,public bathroom,and internet har,respectively,with significant differences among the different groups.ConclusionThe MSM from different venues had high risk behaviors and the prevalence of HIV/STD among the MSM in Changzhou city was very high.More effective interventions should be taken apart from publicity and education.