Abstract: ObjectiveTo investigate HIV/AIDS/STD risk behaviors and influencing factors among men who have sex with men (MSM) in Lianzhou City, Guangdong Province.MethodsRespondent-driven sampling, snowball sampling, and network recruiting were applied to recruit MSM from October 2014 to August 2015. A structured questionnaire survey and the blood collection of participants were carried out simultaneously. The contents of the survey included demographic characteristics, sexual behavior, HIV/AIDS intervention service, and the HIV/AIDS related knowledge and attitude. Logistic regression was used to analyze factors influencing high risk behaviors. ResultsA total of 312 MSM were recruited. Their average age was (30.53±11.52) years. Of the participants, 58.65% had the education level of high school, secondary specialized school, or below; main occupations were student (22.44%), worker (22.44%), and service personal (20.19%); 61.86% were unmarried; 62.18% were homosexual. The awareness rate of HIV/AIDS was 75.32%. In the past one year, the coverage of intervention service was 31.41%. During the past six months，79.81% (249/312) of them had anal sex with male partners, but only 24.10% used condom every time when having anal sex, and the condom using rate for the latest anal sex was 44.18% (110/249); 28.85% of the MSM had sex with females and only 14.44% of them used condom every time. The positive rates of HIV antibodies, HBsAg, and syphilis antibodies were 12.18%, 5.92%, and 2.96%, respectively. No cases were found to be positive for HCV antibody. In the multivariate logistic regression, the subjects who were 20 years old or older when having first sex with males were not more likely to have multiple male sexual partners (OR=0.44), those who had monthly income above 3 000 Yuan were more likely to have multiple male sexual partners (OR=4.66), those who had lower level of education were not more likely to use condoms each time (OR=0.30), and those who did not have related diseases tested voluntarily (OR=3.39) and the male sexual partners were non-fixed or both (OR=1.73) were much easier to have unprotected anal intercourses with male partners.ConclusionHIV infection rate is high, awareness of HIV/AIDS knowledge is low, and high risk behaviors exist generally among MSM in Lianzhou. It is necessary to take targeted publicity and interventions including peer education, network intervention, and school education for HIV prevention.