Abstract: ObjectiveTo explore the trend of HIV prevalence among men who have sex with men(MSM)in Beijing,we conduct three consecutive,cross-sectional surveys of HIV prevalence and related risk behavior among MSM in Beijing from 2004 to 2006.MethodsWe applied respondent-driven-samlping(RDS)to recruit MSM for demographic characteristics and HIV-risk related behavior.Blood specimens were drawn for HIV,syphilis,and Hepatitis B and C tesing.ResultsA total of 325 MSM participated in 2004,427 in 2005,and 540 in 2006.HIV prevalence increased from 0.4% (95% CI=0.1~0.8)in 2004 to 4.6% (95% CI 2.2~7.6)in 2005 to 518% (95% CI 3.5~8.6)in 2006.This rise was accompanied by an increase in having multiple sex partners,self-reported history of STD,and serological evidences of syphilis infection.ConclusionThe application of RDS efficientyly recruited samples of MSM in Beijing in three consecutive years and detected a rising prevalence of HIV and related risk behavior.Practical measures to stop the further spread of HIV in this population are urgently needed.