Abstract: Objective To estimate the effect on renal function of children exposed to environmental lead.Methods Children were divided into four groups based on thier blood lead levels.The first group blood lead level were less than or equal to 0.483μmol/L;The second group blood lead level were more than 0.483μmol/L,or less than or equal to 0.965μmol/L;The third group blood lead level were more than 0.965μmol/L,less than or equal to 2.172μmol/L;The fouth group blood lead level were more than 2.172μmol/L.The activities of NAG,γ-GT,ALP,LDH and the content of total proteinβ₂,-MG,Alb,IgG in the urine of different groups children were determinded.Results The higher of the blood lead levels of children,the higher of the activities of the enzymes in urine,especially NAG andγ2GT;The activities of NAG and LDH were significantly higher in the third group than those in the first group.When the blood lead levels were more than 2.172μmol/L,the contents ofβ₂-MG in urine were significantly increased,and the contents of other kinds of protein in urine were not significantly changed.Conclusion When the blood lead levels were more than 0.965μmol/L,the renal functions of children exposed to environmental lead had been damaged in a certain degree,and when blood lead levels more than 2.172μmol/L,the damaging was more extensive;Determinitions of NAG,LDH,γ-GT,ALP andβ₂-MG were regarded as early monitoring renal damaging index in children exposed to environmental lead.