Objective:To study the effect of cold and heat enviroment stimulation on Th1/Th2 cytokines of diethylnitrosamine(DEN)-induced liver cancer in rats.Methods:The liver cancer model of rats was established by intragastric administration of DEN (a dosage of 10mg/kg,once a day,five times a week for 14 weeks).These rats received cold and heat stimulation respectively lasted for 3 hours every day for 20 weeks.Hematoxylin and eosin (HE) staining was used to examine the changes of liver pathology.The mortality, tumor-formation rate and the ratio of spleen and weight were measured and the concentration of IL-2、IFN-γ、IL-10、IL-4 in blood serum of rats were detected by ELISA.Results:Compared with model group,the mortality,tumor-formation rate,the ratio of spleen and weight and the concentration of IL-10、IL-4 were increased,the concentration of IL-2、IFN-γwere decreased in heat stimulation group,while the opposite results were observed in cold stimulation group.And the difference of the two groups is significant.Conclusion:Some impart of long-term cold and heat stimulation on formation and prognosis of tumor can be observed in DEN-induced rat model of liver tumor.Causeing the change of concentration of Th1/Th2 cytokines may be one of the mechanisms.