Objectives To study the characteristic of pulmonary embolism (PE) in contrast-enhanced CT. Methods The radiological features were described in 20 patients with lobar and proximal PE diagnosed with a Toshiba Xpress/SX CT scanner after contrast material was administrated. Results There were 7 cases of pulmonary embolism (PE) secondary to lower limb deep vein thrombosis (DVT), of which 2 cases were related to sauna bath. We grouped the cases according to their extensiveness of embolism: mild, moderate, severe, or complete embolism. Mild embolism: the emboli occupied less than 30%, of the inner diameter of pulmonary artery (PA). Median embolism: the emboli occupied 30～50% of the PA diameter. Severe embolism: the emboli occupied over half of the PA (50%), but there were contrast flow. Completed embolism: there was no contrast found around the emboli. The direct sign of PE was a filling defect or no opacification in the affected branch of pulmonary artery (PA). There were 9 other secondary signs: ①widen PA, ②enlarged right ventricle and the right atrium, ③increased translucency of the lung and decreased bronchovascular shadows, ④shrunken pulmonary veins liked dried rattan, ⑤decreased left atrium and the left ventricle size, ⑥shifting of interventricular septum to the left and posterior direction,⑦The lateral lung parenchyma demonstrated in a triangular shape,⑧pleural effusion and ⑨pericardiacle effusion. Conclusions The diagnosis of PE was revealed by 10 radiological signs by contrast-enhanced CT:With full understanding of the pathophysiological basis of these 10 signs:correct diagnosis of pulmonary embolism can be made. PE is commonly caused by lower limb. And sauna bath is one of the main predisposing causes.