Objective：To investigate the clinical value of islet autoantibodies（A） and islet β-cell functions（a total of four kinds of combination：A+β+，A+β-，A-β+，A-β-）in the differential diagnosis and classification in patients with ketosis-prone diabetes（KPD）. Methods：A total of 134 patients with newly diagnosed KPD were included，who were admitted to West China Hospital from January 2000 to December 2010. They were divided into four categorical groups based on the presence or absence of autoantibodies（A+ or A-） and β-cell functional reserve（β+ or β-）：A+β+（n=15），A+β-（n=13），A-β+（n=77），A-β-（n=29）. Islet autoantibodies includ－ing islet cell antibody，insulin autoantibody and glutamic acid decarboxylase antibody were measured. The clinical characteristics and biochemical parameters were compared among four groups. Results：Of the total 134 patients，there were differences in body mass in－dex（BMI），waist and hip circumference ratio（WHR），plasma glucose concentration，glycosylated hemoglobin A1c（HbA1c） and triglyc－eride（TG） in four groups（BMI：P=0.000；WHR：P=0.026；blood glucose：P=0.009；HbA1c：P=0.001；TG：P=0.044）. BMI and WHR were significantly higher in patients of A-β+ than in patients of A-β-（BMI：P=0.005；WHR：P=0.004）. Plasma glucose concentration and hemoglobin A1c （HbA1c） of patients in A-β+ group were lower than those of patients in A-β- group（plasma glucose concen－tration：P=0.036；HbA1c：P=0.010），but the triglyceride levels were significantly higher in A-β+ group than in A-β- group（P=0.015）. Conclusion：Patients with KPD show significantly different levels of β-cell function，clinical and biochemical characteristics，which may need different therapeutic strategies. Aβ solution based on the autoantibodies（A） and β-cell functional reserve can provide ref－erences in the treatment of KPD.