A new serological method: Avidin-Biotin peroxidase complex-ELISA (ABC-ELISA) was used in the detection of HBsAgin the serum of a population. The serumsamples were tested by the ABC-ELISA,ELISA, RPHA and RICEPA methods. Thesensitivity of the ABC-ELISA method ascompared with the other three methods isin the order of ABC-ELISA ELISA,R-PHA,RICEPA. When ABC-ELISA was used instead ofELISA, the results showed that the detec-tion rates of HBsAg raised from 16.07% to23.58%. Based on these experiments, ithas been dem...