The major mode of HIV/AIDS transmission in China is now heterosexual activities, but risk for HIV and sexually transmitted diseases (STDs) may differ among different strata of female sex workers (FSWs). Respondent-driven sampling was used to recruit 320 FSWs in Guangdong Province, China. The respondents were interviewed using a structured questionnaire, and tested for HIV, syphilis, gonorrhea, and Chlamydia. The street-based FSWs had lower education levels, a higher proportion supporting their families, charged less for their services, and had engaged in commercial sex for a longer period of time than establishment-based FSWs. The proportion consistently using condoms with clients and with regular non-paying partners was also lower. The prevalence of syphilis, gonorrhea, and Chlamydia was higher among street-based sex workers. Being a street-based sex worker, having regular non-paying sex partners, and having non-regular non-paying partners were independent risk factors for inconsistent condom. Street-based FSWs had more risk behaviors than establishment-based FSWs, and should therefore be specifically targeted for HIV as well as STD intervention programs.