Abstract: Objective To study the mechanism of NiSO₄,K₂Cr₂O₇,CoCl₂ and the mixture to damage kidney of mice in order to provide theoretical evidence for preventing and curing joint toxicity of the mixture.Methods Several groups of mice were exposed respectively to NiSO₄,K₂Cr₂O₇,CoCl₂ at dose of 2.5mg/kg,0.14mg/kg,0.41mg/kg and a mixture of them at 0.09mg/kg,0.17mg/kg according to the ores percentage of average content(Ni:Cr:Co=0.26:0.30:0.02)in the Jinchuan area through intraperitoneal injection for 10 days.Renal tubular cell membrane were prepared to assess the activity of Na⁺.K⁺-A TPase,Ca²⁺ -ATPase with enzyme biochemical assay.Results The enzyme activity of Na⁺.K⁺-ATPase,Ca²⁺-ATPase were inhibited obviously by NiSO₄,K₂Cr₂O₇,CoCl₂ and the mixture,and the mixture toxicity were stronger than that of NiSO₄,K₂Cr₂O₇,CoCl₂ lonely.Conclusion This could be the mixture that caused joint toxicity in the body of mice to inhabit the activity of Na⁺.K⁺-ATPase,Ca²⁺-A TPase of renal tubular cell membrane so as to damage the kidney.However,the mechanism of joint toxicity on the mixture should be studied further.