To investigate transformation of mesangial cell in rats with IgA nephropathy and effect of Chinese materia medica prescription Shenluoning.Methods:SD rats were divided into normal group,model group,Shenluoning group,and Shenyan Kangfu tablet group;The model of IgA nephropathy of rats were established by co infection of bovine serum albumins(BSA) and staphyloentero toxin B (SEB);RBC,BUN,Cr were examined,pathology of nephridial tissue were investigated by optical and electron microscopy and fluorescent immunoassay;Expression of Mesangial Cell α,α SMA,FN,ICAM 1 were observed by Immunohistochemistry and computer image analysis.Results:Expression of Mesangial Cell α,α SMA,FN,ICAM 1 of model group were positive(P<0.01),and in this group,IgA heavily deposit in mesangial region,intercapillary cells moderately proliferated,matrix increased,and blood capillary stenosis could be seen,RBC,BUN,and content of Cr in blood obviously increased;In Shenluoning group and Shenyan Kangfu tablet group,expression of Mesangial Cell α,α SMA,FN,ICAM 1 significantly decreased(P<0.01),deposit of IgA and proliferation of matrix slightly increased,RBC,BUN,content of Cr in blood obviously decreased.Conclusions:Phenotypic transformation of Mesangial cell occur in rats with IgA Nephropathy.Chinese materia medica prescription Shenluoning can repress the transformation,improve clinical and pathological change,Shenluoning is effective in treating IgA Nephropathy.