Abstract: Objective To understand the status of knowledge,behavior feature and prevalence of AIDS/sexually transmitted disease(STD) and to provide scientific evidence for developing intervention model and evaluating intervention effect in floating population.Methods Subjects were selected by stratified cluster sampling in Hefei city from floating population.The subjects were surveyed with a structured questionnaire by face-to-face interview and detected for syphilis,human immundeficiency virus(HIV) and hepatitis C infection.The data were analyzed with SPSS 17.0.Results A total of 1 657 floating people,including 993 males and 664 females with an average age of 32.43±12.05 years,w ere surveyed.The rate of correct recognition about AIDS transmission route was 67.30%.All subjects had poor know ledge about AIDS non-transmission route with a correct know ledge rate of 46.5%.The incidence of commercial sexual behavior and drug abuse was low,but the awareness of voluntary test,safe sexual behavior and seeking medication for STD was poor.Multiple linear step regression analyses show ed that factors of influencing scores of awareness were age,hometow n,education,and income.The prevalence of hepatitis C and syphilis was 0.3% and 0.4%,respectively,among the subjects.Conclusion The education on knowledge of non-transmission route of AIDS/STD and medication,counseling and condom use should be improved among floating population to control the diseases.