Abstract： Objective： To observe the effect of Shenqi Jiangtang granules combined with Sitagliptin Phosphate Tablets on insulin resistance and vascular endothelial function in patients with type 2 diabetes mellitus complicated with obesity. Methods：A total of 116 cases of patients with type 2 diabetes mellitus complicated with obesity were selected as the research objects and were divided into the control group and the observation group according to the random number table method， with 58 cases in each group. The control group was treated with Sitagliptin Phosphate Tablets， and the observation group was additionally treated with Shenqi Jiangtang Granules based on the treatment of the control group. The changes in fasting blood glucose(FBG)， homeostasis model assessment of insulin resistance(HOMA- IR) indexes and homeostasis model assessment of β cell function(HOMA- β) indexes were compared between the two groups；the levels of tumor necrosis factor-α(TNF-α)，interleukin-6(IL-6)，nitric oxide(NO) and endothelin (ET- 1) in serum were examined； the changes of flow- mediated vasodilatation(FMD) were measured. Results： After treatment， FBG and HOMA- IR in the two groups were decreased when compared with those before treatment， and HOMA- β indexes were increased(P＜0.05)； FBG and HOMA- IR in the observation group were lower， and HOMA- β was higher than those in the control group(P＜0.05). After treatment，the levels of TNF-α and IL-6 in serum in the two groups were decreased when compared with those before treatment(P＜0.05)，and the levels of TNF-α and IL-6 in serum in the observation group were lower than those in the control group(P＜0.05). After treatment， the levels of FMD and NO in the two groups were increased when compared with those before treatment， and the levels of ET- 1 were decreased(P＜0.05)； the levels of FMD and NO in the observation group were higher， and the level of ET- 1 was lower than those in the control group(P＜0.05). Conclusion： The therapy of Shenqi Jiangtang Granules combined with Sitagliptin Phosphate Tablets for patients with type 2 diabetes mellitus complicated with obesity can effectively reduce insulin resistance and improve vascular endothelial function.