Objective To investigate the evaluation significance of plasma D-dimer level for the prognosis in acute exacerbation of chronic obstructive pulmonary disease(AECOPD) excluding pulmonary embolism(PE).Methods The patients with AECOPD were collected from the respiration department and emergency internal medicine department of the Affiliated Hospital of Nantong University during 2007-2011.Thirty-five AECOPD cases of D-dimer positive and excluding PE and lower extremity deep venous thrombus(DVT)by CT angiography served as the experimental group and 35 cases of D-dimer negative as the control group.The differences in the first time hospitalization duration,GOLD grade,mortality rate,re-hospitalization times within 4 years,times of admission to ICU,times of intracheal intubation,rehospitalization and outside-hospital mortality rate were compared between the two groups.The receiver operatingcharacteristic(ROC)curve was applied to evaluate the short-term and long-term prognostic capacity of D-dimer.The t test at the follow up end point was used to analyze the D-dimer level in the death group and the survival group.Results The D-dimer level,length of hospital stay,death number of first time hospitalization,times of re-hospitalization,times of admission to ICU,times of intubation,re-hospitalization and outside-hospitalization mortality rate and total mortality rate had statistical differences between the experimental group and the control group(P＜0.05);but the differences in the age,gender and GOLD grade between the two groups had no statistical significance(P＞0.05).The sensitivity of D-dimer＞1 165 μg/L for predicting the death number of the first time hospitalization was 87.5 ％,and the specificity was 80.6 ％.The sensitivity of D-dimer＞ 865μg/L for predicting the mortality rate of re-hospitalization and outerside-hospital was 78.9 ％,and the specificity was 74.5 ％.The survival curve graph during the follow up period in the two groups revealed that the survival time and survival rate had statistical difference between the two groups.The D-dimer level in the death group was significantly higher than that in the survival group with statistical difference(P＜0.05).Conclusion The D-dimer level is an independent risk factor affecting the short-term and longterm prognosis of AECOPD.