Abstract： Objective： To observe the clinical effect of Liuwei Dihuang pills combined with western medicine for type 2 diabetes mellitus ， and its effect on islet function ， inflammatory factors ， and immune function. Methods ： A total of 100 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，50 cases in each group. The control group was treated with oral hypoglycemic drugs or insulin injection treatment，and the observation group was additionally treated with Liuwei Dihuang pills based on the treatment of the control group. Both groups were treated for three months. Before and after treatment，the scores of Chinese medicine syndrome，blood glucose indexes，islet function indexes，levels of inflammatory factors，and immune function indexes were compared between the two groups. Results：After treatment，the Chinese medicine syndrom scores in the two groups were decreased when compared with those before treatment(P＜0.05)，and the score in the observation group was lower than that in the control group(P＜0.05). After treatment，fasting blood glucose(FBG)，postprandial 2-hours plasma glucose(P2hPG)， hemoglobin A1c(HbA1c)， homeostatic model assessment of insulin resistance(HOMA- IR)， C- reactive protein(CRP)，tumor necrosis factor- α(TNF- α)，interleukin- 6(IL- 6)，interleukin- 1β(IL- 1β)，and CD8 + in the two groups were decreased when compared with those before treatment(P＜0.05)，and the nine indexes above in the observation group were lower than those in the control group(P＜0.05). After treatment，levels of fasting C-peptide(FCP)，postprandial 2-hours C peptide(P2hCP)，homeostatic model assessment of β-cell function(HOMA- β)，and CD4 +，as well as CD4 +/CD8 + in the two groups were increased when compared with those before treatment(P＜0.05)， and the five indexes above in the observation group were higher than those in the control group(P＜0.05). Conclusion： The therapy of Liuwei Dihuang pills combined with western medicine can effectively reduce level of plasma glucose of patients with type 2 diabetes mellitus， improve their islet function and immune function，and relieve inflammatory responses.