Objective:To investigate the factors influencing the prognosis of patients with acute pulmonary embolism. Methods:The data of 245 patients with acute pulmonary embolism were analyzed retrospectively and the follow-up-visits were completed. The patients were divided into three groups including the acute phase death group,the late death group and the good prognosis group. The clinical data and the reasons of death were compared. Results:There were no significant differences in age,sex,smoking history,hypertension,diabetes,coronary heart disease,rheumatic heart disease,chronic kidney disease,connective tissue disease,pregnancy and cerebrovascular disease in the 3 groups. However,the ratios of malignant tumor and chronic heart failure in the two death groups were significantly higher than that in the good prognosis group,and the ratio of infectious diseases in the acute phase death group was significantly higher than that in the other two groups. Besides,the ratio of chronic lung disease in the late death group was significantly higher than that in the other two groups,and the ratio of surgical history in the good prognosis group was significantly higher than that in the other two groups. The progress of malignant tumor was the main reason of death in all patients. Moreover,there was a considerable proportion of patients died of chronic thromboembolic pulmonary artery hypertension and gastrointestinal bleeding in the late death group. Conclusion:After standard treatment,some of the risky factors of thrombosis did not significantly affect the prognosis of patients. On the other hand,malignant tumors,chronic lung disease,chronic heart failure and serious infectious disease could indicate bad prognosis of acute pulmonary embolism. The risk-stratification based on shock and simplified pulmonary embolism severity index score is an effective method to evaluate the prognosis of patients. We could focus on the occurrence of chronic thromboembolic pulmonary arterial hypertension and digestive tract hemorrhage in the long term follow-up-visits.