Abstract: Objective To investigate the prevalence of HIV,HCV,syphilis infection and AIDS knowledge and related behaviors among men who have sex with men(MSM)in Urumqi.Methods The eligible MSM were given in depth interview by well-trained interviewers,and they were detected for HIV,anti-HCV antibody and syphilis antibody.Results HIV positive rate was 2.16%;syphilis infection rate was 10.82%;anti-HCV positive rate was 1.30% am ong 231 MSM.The subjects had certa in degree knowledge on AIDS.Among them,36.00% claimed always using condom in anal intercourses with men in the past 6 moths;16.88% reported having sex with women.Only 40.00% of the subjects used condom and 12.50% claimed always using condom during intercourses with women.Conclusion There is a high prevalence of HIV and syphilis infection among MSM in Urumqi and effective intervention should be taken to prevent the disease.