Abstract: Pulmonary embolism presents the third most common cause of death in cardiovascular diseases.Recently, the rapid development of imaging technology has gradually increased the detection rate of subsegmental pulmonary embolism.But in fact, due to the lack of specific data including clinical manifestations, potential related complications and long-term follow-up, it remain controversial that respect to clinical significance of subsegmental pulmonary embolism and benefit of anticoagulant therapy.This article reviews the evaluation, diagnosis and treatment of subsegment pulmonary embolism, aiming to provide reference and guidance for clinical treatment of subsegmental pulmonary embolism, broaden cognize for physician who was on the front lines (department of clinic and imaging) on venous thromboembolism.