A model of chronic renal failure of rats was established by using adenine gavaging after unilateral nephrectomy. Treatment group gavaged by green tea decoction and the control group gavaged by Niaoduqing solution for 28 days in succession. Pathological staining of rat renal paraffin sections conducted with Hemotoxylin and Eosin staining method, Periodic Acid-Silver Methenamine staining method, Masson staining method, Sirius red staining method and Mallory staining method. The pathomorphological changes of these five strained samples were observed by optical microscope. The samples of periodic Acid-Silver Methenamine staining, Masson staining, Sirius red staining, Mallory staining were randomly selected for kidney pathology image analysis. Green tea decoction group was better than model group in area of renal interstitial fibrosis, integral optical density of glomerular mesangium and the type I and III distribution area in renal interstitial(P<0.05). It illustrate that the green tea decoction can reduce the patho, ogical damage of renal interstitial fibrosis in rats caused by adenine. Green tea decoction shows effect of anti-renal interstitial fibrosis. And it also inhibits the proliferation of I, III type collagen fibers, which may be the mechanism green tea decoction in the control of the development of renal interstitial fibrosis and chronic renal failure.