To explore the effect of Zhibai Dihuang Decoction combined with metformin blood glucose of patients with type 2 diabetes of yin-deficiency and fire-exuberance pattern. Methods:A hundred patients with type 2 diabetes belonging to yin-deficiency and fire-exuberance pattern were collected and randomly divided into two groups with 50 cases in each by single blind control test. Patients in the control group received metformin with the dose adjusted according to blood glucose, while patients in the treatment group received Zhibai Dihuang Decoction combined with metformin therapy. Fasting blood glucose, postprandial blood glucose and glycosylated hemoglobin were respectively measured before and after 2 months of the observation period. Results:The glucose metabolism in both groups improved. The total effective rate of the control group was 73.91%, that of the treatment group was 93.33%, and the treatment group was superior to that of the control group. Fasting blood glucose (FBG), postprandial 2 hours blood glucose (2hPBG) and glycosylated hemoglobin (HbA1c) in both groups effectively reduced and these indexes of the treatment group showed lower than those in the control group. Conclusion:Zhibai Dihuang Decoction combined with metformin has obvious curative effect in improving type 2 glucose metabolism in diabetic patients of yin-deficiency and fire-exuberance pattern.