Objective: To investigate the effect of cryotherapy on apoptosis in mouse G422 glioma and the relationship between the freeze thaw cycle and apoptosis induction. Methods: Mouse experimental models with glioma was established, TUNEL and DNA gel electrophoresis were applied to detect apoptosis. Results: The results showed that the different freeze thaw cycle could induce apoptosis in G422 glioma cells and the peak of apoptosis was in 24~ 48 h after freezing. Repetition of the freeze thaw cycle induces more apoptotic cells. Conclusions: Cryotherapy could induce apoptosis in mouse G422 glioma, the number of TUNEL positive cells is related to the freeze thaw cycle suggesting that apoptosis induction may be the major mechanism in cryotherapy of glioma with freezing.