HBs Ag positive in the sera of 100 dases by RIA method were compared EIA, RPHA and Latex method. anti HBs positive in the sera of 83 cases by RIA method was compared EIA and PHA method. The results are summarized as follows; 1. Positive rate of HBs Ag in the sera 100 cases was showed RIA (100%), EIA(100%), and RPHA method of auscell(100%), serodia(97%), hepa-s(98%) hepatitis B-Latex method(92%). 2. Positive rate of HBs Ab in the sera of 83 cases was showed RIA(100%), EIA(99%) and PHA method of Serodia(84%), hepa-s(90%). 3. The most sensitive method of the detection of HBs Ag and anti HBs was RIA. There were no significant difference of sensitivity of HBs Ag and anti HBs between RIA and EIA method.