Ventricular septal defects can be divided into five types according to their anatomical location: perimembranous, funnel, myocardial, atrioventricular access type, and mixed type, among which perimembranous ventricular defects are the most common. The timing of surgery for ventricular septal defect is mainly based on the following three aspects: 1, defect site: such as pulmonary artery or double subarterial defect, generally no self-healing possibility, and easy to cause aortic valve prolapse and regurgitation, affecting cardiac function, early surgery is desirable. 2, clinical manifestations: due to the increased blood flow in the pulmonary circulation of ventricular septal defect, the child will have growth retardation, recurrent respiratory infections, congestive heart failure, feeding difficulties and other symptoms, and even complications of bacterial endocarditis, and early surgery is appropriate when the drug cannot be controlled. If the child has good growth and development, normal weight gain, no frequent respiratory infections, and the defect has a tendency to heal itself, the child should be followed up every 3-6 months. There is no urgency to perform surgery. If the child has a large ventricular septal defect without a tendency to heal on its own, surgery can be performed as early as 2-3 months depending on the status of cardiac function and the overall level of the medical team in the unit where the child is seen (such as the cardiac surgery department of Shanghai Children’s Medical Center). If your child has a ventricular septal defect and you are not sure when is the best time for surgery, please do not delay and go to a regular hospital in time.