Objective To examine the current status of the sexual behavior among out‐of‐school adolescent men who have sex with men(MSM)and analyze the influential factors of AIDS infection in order to provide countermeasures.Methods The software SPSS 16.0 was used for cross table analysis and chi square test of questionnaire data and HIV detection data.Results The HIV infection rate was 21.36%.The household registration ,the only child ,living state ,coming out of the closet ,fixed sex‐ual partner ,the way they know sexual partners had no significant effects on HIV infection(P>0.05).Having multiple sexual partners(P<0.05) ,unfamiliar with sexual partners(P<0.05) ,having sex with network friends(P<0.05) ,no condom use in sexual life(P<0.01) ,having no regular HIV testing(P<0.01)were significantly related to HIV infection.Conclusion Reduc‐ing the sexual behavior among out‐of‐school adolescent MSM ,carrying out HIV counseling and testing ,promoting the use of condoms contribute to the reduction of HIV infection.