Abstract: 　Objective??To analyze the level of cardiac troponin I (cTnI) in children with left-to-right shunt congenital heart disease (CHD). Methods In this study, 146 children with secundum atrial septal (ASD) defect, 132 children with ventricular septal defect (VSD) and 300 healthy children were recruited. The levels of cTnI and N-terminal pro-brain natriuretic peptide (NTproBNP) were measured and their correlation with clinical data was analyzed. Results The serum cTnI and NT-proBNP levels in both ASD and VSD patients were significantly higher than those in normal children (H=3.89 and 5.27, P<0.01). The serum cTnI and NT-proBNP levels in VSD patients were significantly higher than those in ASD patients (P<0.05). The ratio of pulmonary to systemic arterial pressure (Pp/Ps), pulmonary vascular resistance index (PVRI) and standardized left ventricular end diastolic volume in VSD patients were significantly higher than those in ASD patients (P<0.05). Multiple regression analysis showed that Pp/Ps was significantly correlated with cTnI in VSD patients. (β=0.81, SE=0.03, P=0.000). Conclusions Significant volume and pressure overload due to a left-to-right shunt induce myocardial injury and could lead to irreversible myocardial remodeling in children with CHD. The serum cTnI level is a sensitive biomarker for myocardial damage in VSD patients.