Objective To compare the Modified Early Warning Score(MEWS),blood glucose value score and the two scores combined with the ability to predict the prognosis of patients with acute complication of diabetes mellitus,and to explore the most suitable assessment tools. Methods 419 patients with acute complica-tions were collected in diabetic mellitus. To put the admission time as the inital observation point,MEWS score, blood glucose value score and MEWS combined with blood glucose value were assessed and compared between the time point of admission and discharge by ROC curve.Results Using death as a prediction index,MEWS score of subjects operating characteristic area under the curve of AUCROC was 0.875 and the optimal cut-off value of was over 4 in the sensitivity of 78.43%,specificity of 85.60%,the positive predictive valueof 43.01% and the negative predictive value of 96.63% independently. The average score of blood glucose area under ROC curve AUCROC was 0.681 and the optimal cut-off value was 2 in the sensitivity of 50.98%,the specificity of 85.33% the positive predictive value of 73.4% and negative predictive value of 67.5% respectively. Two scores combined with area under ROC curve AUCROCwas 0.982,and the optimal cut-off value was over 7 in the sensitivity of 94.12%,the specificity of 95.65%,the positive predictive value of 75% and the negative predictive value of 99.15% individually. Conclusion For predicting the prognosis of patients with acute complications of diabetes,the combined scores are better than the pure MEWS score and blood glucose value.It is worth of clinical application.