Abstract： Background Female sex workers (FSW) were high-risk population for HIV and other sexually transmitted diseases (STD) earlier,and now are an important driver of the HIV/AIDS epidemic in China.Sentinel surveillance for FSW was set up to monitor the trend of HIV prevalence and risk behavior-related HIV infection.This study collected the data on street-based FSW from HIV sentinel surveillance system to understand HIV and syphilis infections,risk behaviors,and intervention in China from 2010 to 2012.Methods The study population was the street-based FSW who were recruited for the national HIV integrated biological and behavioral surveillance between 2010 and 2012.Demographic information,HIV-related risk behaviors,and HIV and syphilis testing results were described and trend analysis was performed.Results Between 2010 and 2012,the number of street-based FSW surveyed was 3725,3425,and 3335,respectively.HIV knowledge awareness rate significantly increased from 74.6％ in 2010 to 76.8％ in 2011 and 82.2％ in 2012 (P ＜0.01).More FSW consistently used condom in the last month (49.0％ in 2010; 51.0％ in 2011; and 59.0％ in 2012) and in the last commercial sex (72.0％ in 2010; 78.5％ in 2011; and 80.0％ in 2012) over time.The proportions of individuals who received HIV testing in the last year were 31.2％ (2010),37.0％ (2011),and 36.9％ (2012) (P-trend ＜0.01).HIV prevalence rate changed from 1.5％ in 2010 to 1.4％ in 2011 and 2.3％ in 2012 (P-trend=0.01).Syphilis prevalence rate was 6.9％,7.2％,and 7.1％ in the same period.The top three provinces with the highest average HIV prevalence rates over the 3 years were Guangxi (5.9％),Yunnan (4.2％),and Sichuan (1.2％).Conclusions Street-based FSW are at high risk of HIV and syphilis infections.Intervention efforts need to target streetbased FSW who are of old age and minority,who use illicit drugs and have syphilis infection.