【Abstract】ObjectiveTo investigate the proliferation rate of HepG2 cell after multiple thermotherapy and the possible reasons related to it. MethodsAfter HepG2 cell were treaded by ten repeated cycles of heat exposure at 43 ℃ for 80 minutes twice a day, the doubling time of cell was analyzed， and the cell cycle, bcl2 mRNA and bax mRNA were detected. ResultsThe proliferation rate of HepG2 cell which treated with heat speeded up, the percentage of G2 and S in cell cycle increased, the expression of bcl2 mRNA strengthened and the rate of bcl2/bax increased. ConclusionThe speeded proliferation of HepG2 cell after multiple thermotherapy is related to its high percentage of DNA duplicated and dividing cell, strengthened expression of bcl2 mRNA and increased rate of bcl2/bax.