Many heat shock proteins, e.g. gp96, HSP90, HSP70, etc have elicited rejection and immunotherapy immunogenicity of tumor and infectious diseases. Further study indicated that hsps can chaperone the endogenous repertoire of peptides, and the antigenicity of hsp-peptide complexes lies in the peptides, not HSPs. HSPs present peptides associated with them to MHC class I molecules for recognition by CTL and memory T cells, and elicit cellular immune responses. The latest finding shows that gp96 may present antigenic peptides directly to T lymphocytes functionally as MHC. In recent years the mechanism of immunogenicity and advantages as vaccine therapy of gp96 and HSP70, the two main hsps in mammals have been studied in detail, which offers a new opportunity for immunotherapy of hepatitis B and hepatocellular carcinoma.