Objective To investigate the effects of 201B on anti-glomerular basement membrane(GBM) nephritis in rats.Methods Anti-GBM nephritis model was elaborated by rabbit anti-rat GBM antibody in jection in SD rats in this study.The rats were divided into three groups: 201B treated group(0.46gokg-1od-1,ig),untreated nephritis control group and normal control group.201B was administered daily after injection of anti-GBM IgG.All the rats were observed urinary protein at the 4th day,the 14th day and the 21st day.At the same time,the kidney specimens were collected.Results Rats injected with rabbit anti-GBM Ab developed heavy proteinuria by 4th days,and serum creatinine and serum urea appeared which kept on the rising.Glmerular hypercellularity,crescents,and protein casts were observed in nephriticrats.By electron microscopy,the thickening of GBM and loss of foot processes were seen.But,all pathological changes obviously turned for the better in 201B treated group.Conclusion 201B could inhibit the progression of rats anti-GBM nephritis.