With the development of modern medical technology and the popularity of imaging technology, many children with congenital heart disease are detected by echocardiography in the neonatal period, and atrial septal defect and ventricular septal defect are the most common congenital heart diseases, with an incidence of about 0.1-0.4% in newborns, accounting for 20-30% of all congenital heart diseases. Parents of children with atrial septal defect and ventricular septal defect have varying degrees of questions and confusion about how to determine the severity of their child’s disease and how to choose the appropriate timing and treatment! As the atrial septal defect is located between the left and right atria where the pressure in the heart is low, the fractional flow is much lower than that of the ventricular septal defect, so it is generally not necessary to operate in infancy, but can wait until about 2 to 3 years old before considering treatment. The subtricuspid septal defect also has the potential to reduce fractional flow due to adhesions to surrounding tissues. Even if the defect does not close on its own, it usually does not pose a serious health problem. If the septal defect is large, it can have a serious impact on the child in the first few months of life. After the first 1-2 weeks of life, as the pressure in the right ventricle decreases, blood flow begins to flow from the left ventricle through the septal defect into the right ventricle, where resistance is relatively low, and congestive heart failure gradually develops. Pulmonary artery blood flow then continues to increase, causing the walls of the pulmonary vessels to thicken as a result, producing a severe consequence of increased pulmonary artery pressure, which can develop into cyanosis in later stages. Early increases in pulmonary artery pressure are reversible, but gradually progress to irreversible lesions. From a therapeutic point of view, surgery is a high-risk area due to the small weight, underdeveloped organs and fragile tissues of the child before the age of half a year. When the child weighs 10 kg or more and reaches the age of 1 year or more, the risk decreases significantly and stabilizes in a lower risk area. Recommendations: 1. When an infant or child is initially found to have a ventricular septal defect, immediate surgical treatment is usually not recommended, but rather clinical observation or treatment of congestive heart failure with medication to allow the septal defect to close on its own with the continuation of time. 2. When the ventricular septal defect is large, if the child grows well during the first few months, indicating that the size of the ventricular septal defect will not cause congestive heart failure, observation can continue for early surgery after reaching the aforementioned low-risk area. 3. If the child has a large ventricular septal defect with more than moderate pulmonary hypertension, poor growth in the first few months, combined with congestive heart failure and recurrent respiratory infections, early surgery is often required, even in the high-risk area for surgery, which must be carefully considered by the parents of the child due to the high risk of surgery. Atrial and ventricular defects are treated by open-heart surgery and internal blocking! It is advisable to consult a medical professional for the specific treatment option! It is also important to note that if the size of the atrial septal defect and ventricular septal defect do not match the symptoms, the child should be alerted to the possibility of other cardiac malformations in combination.