Abstract: Objective The present study was designed to investigate the STD/HIV-related behaviors of MSM in Jinan City and provide a scientific basis for the formulation of strategies for the prevention and control of behaviors among the population. Methods A survey was made on MSM by questionnaires in some places where MSM activities took place in Jinan and in the VCT clinics of Jinan Municipal CDC to collect all the information concerned. Results A total of 63.9% of the 656 MSM surveyed admitted that they were homosexual, with 31.3% of the subjects being bi-sexual. 86.0% of the surveyed had unprotected anal intercourse with male partners in the past six months, with 3.4% of them getting their homosexual service by pay and 4.8% of them providing men with sexual services for money. The rate of condom use in their homosexual activities was 28.5% in the past six months, with the rate in their heterosexual activities in the past six months and in the latest sex being 15.5% and 35.7%, respectively. The number of sexual partners for the most active homosexuals amounted to 50 persons with a mean of 3.856.03 persons. STD-related symptoms occurred in 96 subjects but only 10 of them had STD tests and treatment. Conclusion Both homosexuality and bi-sexuality exist among the MSM in Jinan. There is a risk of HIV transmission by MSM through heterosexual activities. High-risk sexual behaviors among homosexual partners are pervasive. So it is imperative to carry out targeted health education and behavior interventions.