Objective To establish the decision tree model of Yang deficiency syndrome and clinical conventional indexes in type 2 diabetes mellitus patients.Methods Syndrome decision and clinical indexes collection from 249 type 2 diabetes mellitus patient were observed and analyzed.Tree structure model were built to summarize the correspondence between Yang deficiency syndrome and clinical conventional indexes based on T test,nonparametric analysis,and Spearman correlation analysis.Results The Yang deficiency syndrome accounted for 31.33％ of 249 type 2 diabetes mellitus patients.The accuracy identification rate of tree structure model of Yang deficiency syndrome with four core index,such as LPa、FT3、TSH、FINS was 84.74％,the sensitivity and specificity were 74.36％ and 89.47％.Conclusion Decision tree model can identify Yang deficiency syndrome of type 2 diabetes mellitus patients clearly and more intuitive.Decision tree model can provide the chance of syndrome objective.