A seroepidemiological study on HBV infection was conducted among female prostitutes in houses of detention in Guangzhou and Fuzhou in 1989, 1990 to understand the situation of sexually transmitted HBV infection in selected areas of China, and prevalence of HBV infection in sexual misbehavior populations. The incidence of HBV infection was 84.82% among the population, and 21.6% was HBsAg positive. The prevalence of HBsAg was significantly higher in prostitutes than in pregnant women. The results show that there is a relatively serious HBV infection in prostitutes in certain cities along coastal region in China.