Abstract: Objective To understand the prevalence of HIV infection and high risk factors in males visiting sexually transmitted disease (STD) clinics in Sanmen, Zhejiang province. Methods The analysis was conducted on the data of sentinel surveillance for AIDS in Sanmen from 2009 to 2013 Results In the sentinel surveillance, 1862 males visiting STD clinics were surveyed, and blood samples were collected from them. Among these males, 76.05% were married and 87.17% were aged 20-49 years. Among the males surveyed, the average awareness rate of AIDS related knowledge was 75.94% and most of them had received no service for HIV/AIDS prevention. Among the 1862 males, 61.38% had sex with female sex workers (FSW) and 36.17% had sex with casual sex partners in recent 3 months and 45.98% had STD in the latest year. The annual differences in the proportion of having sex with FSW or casual partners and STD prevalence in these males during this period had statistically significance (P>0.001). Ten males were detected to be HIV positive (0.54%). The HIV infection rate increased with year. Conclusion The HIV infection rate was low but increased with year in males visiting STD clinics in Sanmen. Among this population, the awareness rate of AIDS related knowledge was low, the proportion of those receiving AIDS prevention service was low and the proportion of those having sex with FSW and causal sex partners was high. It is necessary to conduct health education and behavior intervention in STD clinics through the cooperation between disease control sector and clinical medicine sector.