To investigate the efficacy of Zishen Yijing Huoxue Decoction in treating diminished ovarian reserve(DOR) with kidney deficiency and blood stasis and its effect on T lymphocyte subsets.Methods:A total of 120 DOR patients with kidney deficiency and blood stasis treated at Shaanxi Provincial Hospital of Chinese Medicine from April 2019 to April 2022 were enrolled and randomly divided into an observation group and a control group using a random number table，with 60 patients in each group.The control group received estradiol valerate and cyproterone acetate tablets，while the observation group received Zishen Yijing Huoxue Decoction in addition to the treatment given to the control group.After 6 menstrual cycles of treatment，clinical efficacy，traditional Chinese medicine(TCM) syndrome scores，antral follicle count(AFC)，ovarian artery blood flow parameters，follicle-stimulating hormone(FSH)，estradiol(E2)，anti-Müllerian hormone(AMH)，menstrual conditions，T lymphocyte subsets，and the incidence of adverse reactions were compared between the two groups.Results:After treatment，the total effective rate in the observation group was 88.33%(53/60)，significantly higher than 71.67%(43/60) in the control group(P<0.05).Before treatment，there were no significant differences between the two groups in TCM syndrome scores，AFC，FSH，E2，AMH，ovarian artery blood flow parameters，menstrual conditions，and T lymphocyte subsets(P>0.05).After treatment，the observation group showed significantly lower TCM syndrome scores，FSH levels，CD8+ levels，resistance index，menstrual cycle，menstrual color quality，menstrual volume，and menstrual period scores than the control group.Additionally，the observation group had significantly higher AFC，end-diastolic flow velocity，peak systolic velocity，E2，AMH，CD3+，CD4+，and CD4+/CD8+ ratios than the control group(P<0.05).The incidence of adverse reactions was not significantly different between the two groups(P>0.05).Conclusion:Zishen Yijing Huoxue Decoction is highly effective in treating DOR with kidney deficiency and blood stasis.It can significantly improve clinical symptoms，ovarian reserve function，menstrual abnormalities，and immune function with few adverse reactions.