先天性心脏病（CHD）是婴幼儿因出生缺陷而死亡的最常见原因之一。学龄前期可作为CHD筛查新生儿期的补充阶段，是CHD早筛、早诊、早治的重点年龄段。我国学龄前儿童CHD患病率具有明显地域差异性，房间隔缺损（ASD）、室间隔缺损（VSD）、动脉导管未闭（PDA）是最常见的3种类型，男性多见于较为复杂和严重的CHD，而女性多为单纯性CHD，高海拔与CHD高患病率有关，低收入地区的患病率相对较高。研究学龄前儿童CHD流行病学能够为更精准进行风险预测及一级预防提供更多帮助。

Congenital heart disease (CHD) is one of the most common causes of death from birth defects in infants and young children. Preschool age can be used as a supplementary stage to the neonatal period for CHD screening, which is an excellent period for early screening, diagnosis, and treatment of CHD. The prevalence of CHD in preschool children in China has obvious regional differences. Atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) are the most common three types. Boys more often have more complex and severe CHD, while girls mostly have simple CHD. High altitude is related to the high prevalence of CHD, and the prevalence in low-income areas is relatively high. Studying the epidemiology of CHD in preschool children can provide more help for more accurate risk prediction and primary prevention.