Hepatitis B virus core (HBc) proteins have been used as carrier for foreign epitopes since the 1980s. They could self-assemble into icosahedral particles. Foreign epitopes could be inserted into HBc protein in various protein regions, including the N- or C-terminal and the major immunodominant region (MIR). The factors relevant in the design of HBc particles for vaccine purpose are summarized in this review.