Abstract: Objective This research was done to gain general knowledge of STD/AIDS infections and condom using conditions among Yancheng city's unlicensed prostitutes to provide information for further intervention and control of STD/AIDS. Methods 207 arrested prostitutes that worked in service institutes such as barber's shops, hotels and bath cities received medical examination and STD/ AIDS detection, as well as surveying their condom using conditions. Results STD positive rate was 45.41% among the 207 prostitutes and none were HIV positive. Non- gonococcal urethritis (NGU) was the major detected disease, amounting for 52.13% in the STD positive patients. The prostitutes were mainly unmarried and at early age with low educated level. Conclusion Prostitutes are at high risk of STD and their condom utilizing rates are low. To carry out basic AIDS preventive education and condom utilization in sexually confusing people will play significant role in STD/AIDS control.