The intergrated survey on behavior with the sampling method in HIV/STI sentinel surveillance was conducted in Phu Tho province among female sex workers from February to April 20 12 to determine the rate of HIV infection, assess risk behaviors and coverage of the intervention program. The survey was carried out on 300 sex workers (SWs) are female aged 16 years or older, had sex through vaginal or anal at least once during 1 month before collecting specimens in the province. HIV prevalence was still low with 1,7 percent. The percentage of regularly condom use in last month with clients was 55,6 percent. Phu Tho province needs to boost condom distribution program and increase the coverage of the preventive intervention program for SWs.