Introduction: Diabetes mellitus (DM) is complex disorder characterized by chronic hyperglycemia, the epidemic growth in obesity and elderly population contribute to the prevalence of DM.Traditional Chinese medicine (TCM) has a long history of treatment for DM.Professor Tong Xiao-Lin is an expert in the use of TCM for treatingDM in China,he mentioned the method of "clear away the heat anddirect the turbid downward", which directed preparations that aimed to improve the syndrome,subjective symptoms, and chemical indicators to treat DM.Dahuang Huanglian Xiexin Decoction (DHXD) is a commonly used formula in his clinical practice.Objective:The study aims toprovide clinical evidence in support of DHXDtotreat DM andto introduce a new treatment option for clinicians.Methods:The method of retrospective analysis was applied.Based on Professor Tongs clinic medical records, diabetic patients who met the inclusion criteria and who were seen in the clinic between January 1, 2013 and January 1, 2014 were enrolled in this study.General information (name, sex and age, etc.), symptoms, blood glucose levels and blood lipid levels were recorded and collected, followed by standardized process.The effects of the treatment were evaluated by the changes in FBG,PBG,HbA 1 C, blood lipid series and BMI between the baseline levels and the post-treatment levels at 1-, 2-, 3-or 6-months, the changes in main symptoms were also evaluated.Statistical software SPSS 17.0 wasused to analyze and process the standardized data.Results:One hundred and eighty-three patients with 678 clinical visits were included in this retrospective study.There was a significant improvement in HbA1C at every return visit compared with the baseline level.Mean HbA1C was 7.98±1.7% at 0 month,7.83±1.48% at 1 month, 7.69±1.05% at 2 months,7.12±1.15% at 3 months (p<0.01)and 6.84±1.09% at 6 months(p<0.01).There were also significant improvements in FBG,PBG, blood lipid seriesandBMI.DHXD had effects on reducing the scores of main symptoms and alleviating main symptoms.Conclusions:Preliminary evidence from thisstudy suggests that DHXD could decrease FBG, PBG and HbA1C of diabetic patients, reducing the body weight,correcting disorders of lipid metabolism, and improving diabetic symptoms, the use of DHXDto treat DM may be a new treatment option.Prospective studies are required to provide stronger evidence in future researches.