Objective:To observe the effect of Xueniaoan tablets on the expression of complement regulatory protein CR1 in IgA nephropathy rats. Methods:Totally 36 SD rats were randomized into the normal group,the model group and Xueniaoan group after 4-day adaptive feeding. Complex method was used to establish IgA nephropathy model,and Xueniaoan group was given Xueniaoan at the dose of 7.0 g·kg-1during the 10thweek and the 12thweek,while the normal group and the model group were fed with normal saline, and the administration course was 3 weeks. The 24-h urine protein was detected,CR1 in red blood cells was detected by ELISA,the renal pathological changes were observed under a light microscope after HE staining,and the expression of CR1 was detected by immu-nohistochemistry. Results:Compared with that in the model group,the 24-h proteinuria in Xueniaoan group was significantly reduced, the number of red blood cell CR1 increased significantly (P<0.05), CR1 in renal tissue increased and the renal tissue injury was light. Conclusion:Xueniaoan tablets can delay the renal damages in IgA nephropathy rats through promoting the expression of CR1.