Abstract: Objective To evaluate the effect of peer education on AIDS prevention-related behaviours among men who have sex with men (MSM) in college students.Methods Peer education about AIDS-related behavious was conduted among college student MSM in Nanchang city and face-to-face anonymous questionnaire survey was administered before and after the intervention to assess the effects of the intervention.Results A total of 86 college student MSM participated the baseline survey,and 86 took the follow-up survey.The age of the MSM was from 16 to 25 years.There were 79 (91.9%) MSM came from Jiangxi province.The awareness rate of AIDS was 91.9% for the MSM both before and after the intervention.There were 51 (59.6%) MSM admitting they are gay before the intervention.There were 58 (67.4%) MSM admitting they are gay after the intervention.The proportion of having anal sex with male during the latest week was 26.3% (17) before the intervention and 50.9% (27) after the intervention,respectively,among the MSM,with a significant difference.The percentage of the MSM considering themselves being comprehended and supported increased from 17.7% (15) before the intervention to 75.5% (65) after the intervention.Conclusion Peer education is an efficient way to promote positive change in cognition and behaviour related to AIDS prevention among college student MSM.