Abstract： Objective： To observe the curative effect of Shenqi Jiangtang capsules combined with metformin hydrochloride for type 2 diabetes mellitus with deficiency of both qi and yin syndrome. Methods： A total of 182 cases of patients with type 2 diabetes mellitus were selected and divided into the control group and the observation group according to the random number table method，with 91 cases in each group. The control group was treated with metformin hydrochloride， and the observation group was additionally treated with Shenqi Jiangtang capsules based on the treatment of the control group. Both groups were treated for 12 weeks. The changes in the blood glucose indexes including fasting blood glucose (FBG)，postprandial 2 h blood glucose(P2hBG) and hemoglobin A1c(HbA1c)，the scores of deficiency of both qi and yin syndrome，and the pancreatic β cell function including fasting insulin(FINS)，homeostasis model assessment of insulin resistance index(HOMA- IR) and homeostasis model assessment of β cell function(HOMA-β) before and after treatment and the clinical effects in the two groups were compared. Results：The total effective rate was 95.60% in the observation group and 85.71% in the control group， the difference being significant(P＜0.05). After treatment，the FBG，P2hBG and HbA1c in the two groups were decreased when compared with those before treatment(P＜0.05)； the above indexes in the observation group were significantly lower than those in the control group(P＜0.05). After treatment，the scores of deficiency of both qi and yin syndrome in the two groups were decreased when compared with those before treatment(P＜0.05)，and the score of deficiency of both qi and yin syndrome was significantly lower than that in the control group(P＜0.05). After treatment，the levels of FINS and HOMA-IR in the two groups were decreased when compared with those before treatment(P＜0.05)，and the HOMA-β levels were increased(P＜0.05)； the improvement of the above indexes in the observation group was more significant than that in the control group(P＜0.05). Conclusion：Shenqi Jiangtang capsules combined with metformin hydrochloride has an obvious curative effect in treating type 2 diabetes mellitus with deficiency of both qi and yin syndrome，which can effectively control blood glucose and improve the Chinese medicine syndrome and pancreatic β cell function.