A three-year study has been conducted for prevention of infectious hepatitis with supplementation of table salt fortified with 15 ppm anhydrous sodium selenite to the general population of 20,847 persons in a township M.Z. at Qidong County, Jiangsu Province, China. The results showed that the incidence of virus hepatitis infection in the test township was significantly lower than that of controls provided with normal table salt. The incidence rate of infectious hepatitis in the treated township M.Z. was 1.20 and 4.52 per 1,000, whereas the average incidence in the 6 surrounding control townships was 2.96 and 10.48 per 1,000 in 1986 and 1987, respectively. The incidence of Hepatitis B surface antigen (HBsAg+) was 13.2% vs 19.23% for males and 10.42% vs 12.24% for females in the supplemented vs nonsupplemented neighboring township, respectively. Epidemiological studies have demonstrated that a low grain Se content is associated with a high regional incidence of Hepatitis B virus infections.