Objective:To observe the clinical efficacy of Compound Shenlu Granule combined with western medicine in the treatment of aplastic anemia(AA) with syndrome of kidney yang deficiency,and discuss its mechanism. Methods Sixty AA patients with syndrome of kidney yang deficiency were randomly divided into the treatment group and control group,30 cases in each group. The treatment group was treated with Compound Shenlu Granule combined with routine therapy of western medicine,while the control group was only treated with routine therapy of western medicine. The treatment course in both groups was 6 months with follow-up for one year. The clinical efficacy was observed,and the expression levels of Treg and Th17 in peripheral blood and the mRNA expressions of related gene transcription factors including retinoid related orphan nuclear receptor γt(RORγt)and forkhead transcription factor(Foxp3)were compared.  Results: ①The clinical total effective rate was 76.67% in the treatment group and 63.33% in the control group. The clinical efficacy of treatment group was significantly better than that of control group (P<0.05). ②After treatment,there was no statistically significant difference on the expression level of Th17 between the two groups(P>0.05),while there were statistically significant differences on the Treg expression and Treg/Th17 level between the two groups,and the levels of the treatment group were obviously higher than those of the control group(P<0.05). ③After treatment,there was no statistically significant difference on the RORγt mRNA expression between the two groups(P>0.05),while there were statistically significant differences on Foxp3 mRNA expression and the Foxp3/ RORγt level between the two groups,and the levels of the treatment group were obviously higher than those of the control group(P<0.05).  Conclusion: Compound Shenlu Granule combined with western medicine can significantly improve the clinical symptoms of AA patients,and enhance the hematopoietic function. Its mechanism may be associated with up-regulation of Treg cells and Foxp3 mRNA expression and increase of Treg /Th17 ratio.