Abstract: Objective：In order to observe patients type 2 diabetes with metformin hydrochloride, the changes in blood uric acid level and its influencing factors. Methods：Using self-control method, 480 cases of out-patient long-term use of metformin hydrochloride in patients with type 2 diabetes were observed in blood uric acid levels when the periods of selected, wash off period and the resumption of metformin conventional treatment. Also observed in other biochemical indicators, age, duration, blood pressure, body mass index, metformin daily dose of clinical factors such as serum uric acid change. Results：Serum uric acid levels of the patients in these three periods were(376±90)μmol/L，(355±88)μmol/L, (391± 80)μmol/L. Comparison of serum uric acid changes in two periods: selected and washed(P﹤0.05), Comparison of serum uric acid changes in two periods: resumption and washed(P﹤0.05). The 480 cases of the observer as a whole, uric acid changes value during wash off and resumption of metformin conventional treatment as the dependent variable Y (higher = 1; no increase = 0), Age, diabetes history, systolic blood pressure, diastolic blood pressure, body mass index, fasting blood glucose，alanine aminotransferase(ALT),serum creatinine,serum uric acid and metformin daily dose as independent variables (X1-X10) respectively, Logistic step regression analysis were carried out.Variables selected are age, baseline serum uric acid value and metformin daily dose. Conclusion：Serum uric acid level can be elevated mildly in type 2 diabetes patients taking metformin hydrochloride. Elevated levels of serum uric acid have some connection with eld, high baseline levels of serum uric acid and metformin daily dose is too large.