Abstract: ObjectiveTo learn about AIDS related-knowledge, attitude and practice (KAP) among high-risk populations in Beijing. MethodsAnonymous questionnaire survey was conducted among 505 persons incarcerated in correctional system. ResultsThe majority of this high-risk population were married males with low education degree. The awareness rate of AIDS was 63.35%. Most of them believed that AIDS patients need help, but nearly half of them didn't hope to work or live with AIDS patients. Only 20.76% of them used condoms at each sex, 32.48% of them had more than one sex partners. ConclusionIt is necessary to conduct health education and intervention among this high risk population according to the results of the survey, so their awareness of AIDS could be increased and their attitude to HIV/AIDS could be changed in order to control the epidemic of AIDS.