Abstract： Objective To investigate the clinical correlative factors and CT pulmonary angiography (CTPA) characteristics of secondary changes of chest in different types of acute pulmonary embolism. Methods One hundred and fifty-two cases with acute pulmonary embolism diagnosed by CTPA between January 2015 and October 2016 were retrospectively analyzed.They were divided into central(70 cases)and peripheral (82 cases) groups according to the embolization site. The clinical characteristics (including gender, age, risk stratification, etc.), laboratory findings (including D-dimer, etc.) and secondary imaging findings(including enlargement of the main pulmonary artery and enlargement of right heart,etc.)of the two groups were recorded. The parameters including patient age, body mass index, length of hospital stay and laboratory findings between the two groups were compared using independent sample t test or Mann-Whitney U test. The other variables including the clinical characteristics such as gender, smoking history, etc. and secondary imaging findings between the two groups were analyzed by χ2 test and Fisher exact test.Results The high,moderate and low-risk patients were 7,33,30 cases,respectively in the central group,and 2,16, 64 cases, respectively in the peripheral group. The percentages of moderate and high-risk patients in the central group were higher than peripheral group,the difference of risk stratification between the two groups was statistically significant(P<0.001).In the choice of clinical treatment,there were 5 cases of thrombolytic therapy in the central group and 0 cases in the peripheral group, and the difference was statistically significant (P= 0.019). The other differences of clinical characteristics such as gender and age were not statistically significant(P>0.05).The cardiac troponin I was 0.03(0.01,0.11)μg/L in the central group and 0.01 (0,0.04) μg/L in the peripheral group, and the difference was statistically significant (Z=-2.799, P=0.005).The other laboratory findings such as D-dimer were not statistically significant between the two groups (P>0.05). Among the various secondary changes of the chest on CTPA, the cases of enlargement of the main pulmonary artery,enlargement of right heart,pulmonary infarction,mosaic perfusion were 47,41, 23, 24 cases, respectively in the central group, and 20, 11, 11, 15 cases, respectively in the peripheral group.The percentages of these signs were higher in the central group than peripheral group,the differences were statistically significant (χ2= 28.002,34.214,8.221,5.064, P<0.05). Conclusions Central acute pulmonary embolism is more dangerous and more likely to cause a series of secondary changes.Determining the type of embolism has certain value for clinical doctors to judge the prognosis and choose the treatment.