Background: The aim of this study was to evaluate the efficacy and safety profile of Kludone modified release (MR) in Chinese patients with type 2 diabetes. Methods: Thirty-three Chinese patients with type 2 diabetes on diet control and low-dose sulfonylurea were randomized to Kludone MR or Diamicron MR once daily. Drug doses were increased at 4 week intervals from 30 mg to 120 mg until metabolic control was achieved or the maximum dose reached. Efficacy was evaluated by the fasting plasma glucose and hemoglobin A1c (HbA1c) levels. Results: Fasting plasma glucose significantly decreased from 178.4±38.7 mg/dL to 157.1±39.4 mg/dL (p＜0.01) in the Diamicron MR group, but was not significant in the Kludone MR group after 4 weeks (p=0.084). After 12 weeks of treatment, fasting plasma glucose decreased from 178.4±38.7 mg/dL to 156.0±42.1 mg/dL (p＜0.01) in the Diamicron MR group and from 156.2±45.1 mg/dL to 145.3±45.6 mg/dL (p=0.163) in the Kludone MR group. Hemoglobin A1c between groups was not statistically different (p=0.687), indicating the efficacy of treatment was similar. No adverse event led to withdrawal of the medication. No major episodes were reported in either treatment groups. Conclusion: Once-daily Diamicron MR showed a better trend in improving fasting plasma glucose control compared to Kludone MR regardless of the initial diabetes treatment. However, neither Kludone MR nor Diamicron MR significantly decreased HbA1c levels in this study with limited case numbers. Both drugs were well tolerated with a very small number of patients reporting hypoglycemic episodes.