Rheophoresis improved gel diffusion technique was used for the determination of subtypes of HB antigen (HBAg) according to D (ad + y) and Y (ay +, d--) specificity. Although the relative small number of carriers of antigen was investigated, it seems that the distribution of subtypes is somewhat different from the results found by the american and scandinavian autors and is more similar to the results of Hadziyannis (Greece) and Mosley in Israel. The specifity of serum containing HB antibodies was also investigated. Five sera containing antibodies, revealed both ad and ay subtypes by the counter electrophoresis method, but two of them showed a significantly stronger precipitation line with subtype ay.