Pulmonary thromboembolism (PTE) is a severe and common clinical problem with substantial morbidity and mortality both in US and in Europe. Used to be considered as a rare disease in China, PTE has been increasingly diagnosed in recent years due to the increased awareness and the improvement of imaging techniques. PTE is life threatening without proper intervention at the early onset. Effective treatment can decrease the mortality and the complication of chronic thromboembolic pulmonary hypertension (CTEPH).