Abstract: ObjectiveTo observe the effect of pentachlorophenol so dium on cellular immunity,humoral immunity and macrophage function of mice.MethodsPentachlorophenol sodium was gavaged to mice once time and the dosages of pentachlo rophenol sodium were 25,50 and 100 mg/kg.The changes of immume function were observed at 3,24 and 48 hours after pentachlorophenol sodium treatment.Cellular immunity was measured through Tlymphocyte proliferation;humoral immunity was measured through Blymphocyte proliferation;Macrophage function was measured through phagocytic function and NO production.Results10 mg/kg pentachlorophenol sodium could decrease the weight and relative weight of spleen and thymus when compared with control mice at 3 hours after treatment.At the same time Blymphocyte proliferation,phagocytic function and NO production were also decreased.25 and 50 mg/kg pentachlorophenol sodium reduced the Blymphocyte proliferation not only at the hours after treatment but also the 24 hours after treatment.At 48 hours after treatment there were no difference about all related index between pentachlor ophenol sodium treated mice and control mice.Conclusion25 to 100 mg/kg pentachlorophenol sodium could inhibit the humoral immunity and 100 mg/kg could inhibit the macr ophage function after once treatment.Whereas the cellular immunity was notinfluenced by current treatment.