Abstract: Down’s syndrome (DS) is a genetic syndrome caused by trisomy 21 abnormality. About 50% of DS children are complicated with different types of congenital heart disease (CHD), and the pathogenesis of DS-CHD has not been elucidated. So far, genes that play key role in the pathogenesis of DS-CHD include DSCAM (Down’s syndrome cell adhesion molecule), RCAN1 (regulator of calcineurin 1), COL6A1-A2 (collagen type Ⅵ alpha 1-2 chain), CRELD1 (cysteine rich with EGF like domains 1), ALK2 (activin-like kinase2), and KCNJ6 (potassium voltage-gated channel subfamily J member 6). The pathogenesis of the above genes mainly involves two hypotheses: the gene dose effect hypothesis and the gene mutation hypothesis. This review mainly discusses the mechanism of DS-CHD related genes and the corresponding types of CHD, so as to provide reference for the etiology study of DS-CHD.