Abstract: Objective To provide an overview of the AIDS-related knowledge and high risk behaviors, and the AIDS/syphilis/HCV prevalence among sex workers, male outpatients of STD clinics and floating population, providing the basis for development of intervention strategies. Methods In 2009, according to the Standard Guidelines for Sentinel Surveillance in China,408 male outpatients of STD clinics,401 sex workers and 409 immigrants in Yangquan city received questionnaire surveys and serological test for anti-HIV, RPR and anti-HCV antibodies. Results The awareness of AIDS/HIV prevention knowledge in male outpatients of STD clinics was better than that in the others. No HIV carrier was detected among sex workers and immigrants. For the STD clinic outpatients, one HIV antibody-positive was found, and the infection rates of HIV, syphilis and HCV among them were 0.25%,15.93% and 0.98%, respectively.82.35% of these subjects had commercial sex activities in the last three months, and 54.90% had such behaviors with a temporary sex partner. In the past year,43.14% of them were diagnosed as STD. For the sex workers,1.50% of them were infected with syphilis and 0.50% HCV positive.86.28% of them had used condoms for the latest commercial sex activity, and 74.06% of them used condoms or persisted in condom use in each commercial act for the past month. For the immigrants, the infection rates of syphilis and HCV were both 0.24%.25.43% of them had commercial sex activities in the past year, while 40.38% used condoms each time.47.12% used condoms for the latest commercial sex. Conclusion AIDS surveillance should be intensified for all groups of population, and health education and intervention should be further strengthened for prevention and control of the AIDS prevalence in Yangquan.