Abstract：Objective：To observe the effect of Manshenkangning on expression levels of transforming growth factor-β1 (TGF-β1)，Smad3，Snail1，E-cadherin，α-smooth muscle actin(α- SMA) in the kidney tissue of rats with renal interstitial fibrosis(RIF) due to adenine. Methods： A total of 60 Wistar rats were randomly divided into the control group， the model group，the losartan group，and the Manshenkangning groups of high-dose，medium-dose and low-dose，with 10 rats in each group. Except for the control group， the rat model of RIF induced by adenine was prepared in other groups. After successful modeling，the control group and the model group were given gastric perfusion with distilled water；the losartan group was given gastric perfusion with losartan suspension at the dose of 10 mg/(kg·d)；the groups of high-dose，mediumdose and low-dose were given gastric perfusion with Manshenkangning suspension at the doses of 30，15 and 7.5 mg/(kg·d) respectively ； all the groups were perfused for 30 days. The pathological changes of kidney tissue were observed by HE staining and Massan staining； expression levels of E- cadherin， α- SMA， and TGF- β1 protein were determined by immunohistochemistry；the expression levels of Smad3 and Snail1 protein in kidney tissue were detected by Western blot method； the levels of serum creatinine(SCr)， blood urea nitrogen(BUN)， 24- hour urine protein quantity(24 h MTP) and estimated glomerular filtration rate(eGFR) were measured by automatic biochemical analyzer. Results：When compared with those in the model group，levels of SCr，BUN and 24 h MTP in the losartan group and the Manshenkangning groups were significantly decreased， and levels of eGFR were increased. According to pathological observation， there were tubular atrophy or expansion， obvious infiltration of inflammatory cells， accumulation of adenine metabolite products and bluestained collagen fibers in the glomerulus and renal interstitium in the model group，and the pathological manifestations in the losartan group and the Manshenkangning groups were relatively mild. When compared with those in the model group，the expression levels of α- SMA， TGF- β1 and Snail1 protein in the losartan group and the Manshenkangning groups were decreased，and the expression levels of E-cadherin protein were increased；the expression levels of Smad3 protein in the losartan group and the Manshenkangning groups of medium-dose and high-dose were significantly decreased. Conclusion： Manshenkangning can inhibit the transduction of TGF- β1/Smad3/Snail1 signals， improve E- cadherin protein expression， reduce α- SMA protein expression in RIF rats， and has protective effects on the kidney， which may be one of its mechanisms of anti-RIF.