he subnephritogenic dose of nephrotoxic serum was injected into therat that was preimmunized with normal rabbit IgG in complete Freund's adju-vant eight days before.The results showed that the proteinuria of the ratwas obvious on the first day, and the peak proteinuria occurred on the thirdday.On the 21th day, serum creatinine ( Scr ) was significantly enhanced.The renal histological changes:By immunofluorescence, the main findings onthe first day was thedeposition of rat IgG, C3 and rabbit IgG along CBM.By light microscopy, the number of the cells in the glomerulus on the firstday was significantly increased, with endothelial cells swollen and neutroph-ils infiltrated.On the 7th, 14th, 21th days, the mesangium of the glomerulcapillaries ware widened; mesangial cells proliferated, and there were infi-ltration of inflammatory cells in the interstium.CBM was thicker by PASM stain.By electron microscopy,there were electronic dense deposits in GBM.Thefoot processes of epithelial cell disappeared. The capillary lumens wereblocked by thrombi.In the interstitium: there were inflammatory cells andfibrosis .