When Cmnese Hamster V79 cells were incubated with H₂O₂ of different concentration for 24h and 48h,different degree damages in cells have been found.The activity of SOD decreased and lipid peroxides contents increased in cultured cells.It is also shown that the activies of metabolites,such as GPT,GOT,LDH and CPK,are higher than those in control,is in direct proportion to the H₂O₂ concentration and the incubation time.