Objective:To observe the effects of Qinghua Gushen Paidu Decoction on the expressions of Notch1 and Jagged1 in renal tissue of rats with unilateral ureteral obstruction (UUO),and discuss its mechanism on renal fibrosis. Methods72 SD rats of SPF grade were randomly divided into the sham operation group,UUO model group,Lotensin group and Qinghua Gushen Paidu Decoction(QHGSPD)group. Except the sham operation group,rat model of renal fibrosis obstruction was established by unilateral ureteral ligation in the other groups. After operation,the rats in each group were treated with the corresponding drugs or 0.9% NaCl solution by intragastric administration once a day. 7,14 and 21 days after modeling,the rats in each group were fasted but drunk water freely for one day and then sacrificed. The renal tissue of obstructed side was collected,and the pathological changes of renal tissue were observed after Masson staining microscope. The protein and mRNA expressions of Notch1 and Jagged1 were detected by immunohistochemistry and real-time PCR(RT-PCR)respectively.  Results:As the time of ureteral obstruction prolonged,the degree of renal interstitial fibrosis gradually aggravated. After Masson staining,there was significant difference on the index of renal fibrosis between the model group and sham operation group(P<0.05).Compared with the model group,the degree of renal fibrosis in the QHGSPD group and Lotensin group was relatively alleviated,with statistical difference(P<0.05).The results of immunohistochemistry and PCR showed that the expressions of Notch1 and Jagged1 in renal tissue of rats in the QHGSPD group and Lotensin group were significantly lower than those in the model group(P<0.05).There were no statistically significant differences on the expressions of Notch1 and Jagged1 between the QHGSPD group and Lotensin group(P>0.05).  Conclusion:Qinghua Gushen Paidu Decoction may inhibit the Notch signaling transduction pathway by down-regulating the expressions of Notch1 and Jagged1,which plays a role in improving the renal interstitial fibrosis and protecting the kidney.