In this study, we analyzed the transcribed regions and splicing sites of the SMAD3 gene in a large cohort of CHD patients and controls and found that the variant rs2289263 in the SMAD3 gene was associated with the risk of VSD in the Chinese Han population, demonstrating the involvement of the SMAD3 gene in the VSD etiology. The gene discussed is SMAD3; the disease is ventricular septal defect.