1.Definition: Arterial duct is an important channel of fetal circulation, which is closed to become arterial ligament within a short time after birth, if not closed, called arterial duct unclosed. 2, incidence: arteriovenous ductus arteriosus is one of the common congenital heart disease, accounting for 21% of congenital heart disease, PDA is affected by hereditary factors, the ratio of men to women is about 1:2. 3, closure: arteriovenous ductus is divided into physiological closure and anatomical closure. Physiological closure with the infant’s first breath, the alveoli are expanded, pulmonary vascular resistance then decreases, pulmonary artery blood directly into the lungs, not through the ductus arteriosus, the fetal circulation transposition adult circulation. Anatomic closure occurs with 2-3 weeks of ductal fibrosis. Closure is also affected by prostaglandins, blood oxygen, bradykinin, etc. 4, typing: divided into tubular, funnel type, window type, dumbbell type, aneurysmal type. 5, clinical manifestations: PDA signs and symptoms depend on the size of the duct, pulmonary vascular resistance, age at the time of discovery and the presence of other malformations. The indication of small fractional flow can be heard murmur, rarely have conscious symptoms. Those with high fractional flow will present with poor development, thinness, sometimes fatigue, dyspnea, and frequent pneumonia that is not easily controlled. If the elevated pulmonary artery occurs later, severe Eisenmenger’s syndrome will occur causing general cyanosis, in which case the opportunity for surgery will be lost. 6. Diagnosis: Cardiac ultrasound can make a clear diagnosis. 7.Treatment: The presence of PDA in children and adults is an indication for surgical closure, and the diagnosis is clear that surgical treatment is needed. Severe pulmonary hypertension and reverse shunt, the unclosed duct is an important channel of blood drainage from the right heart, which cannot be surgically closed and is a contraindication to surgery.