Objective:To determine the intervention measures for the decrease of cerebral tissue oxygen saturation during anesthesia for the congenital heart disease in children.Methods:Twenty-eight children with cardiac surgery were enrolled.Anesthesia was deepened with propofol (3 mg/kg) intravenous injection.The data of cerebral tissue oxygen saturation(SctO2),mean arterial pressure (MAP),HR,bispectral index (BIS),arterial partial pressure of oxygen (PaO2),arterial partial pressure of carbon dioxide (PaCO2),hemoglobin (Hb) and middle cerebral artery (MCA) mean flow velocity (Vm) at different points were collected after intravenous injection ofpropofol at 3 mg/kg.The changes of SctO2 and the influential factors were analyzed.Results:SctO2 decreased by 4.99％ after deepen anesthesia,with 95％ CI 4.33％ to 5.65％ (P＞0.05).There was no significant differince in MAP,PaO2,PaCO2,and Hb between the time points after deepen anesthesia and the baseline (P＞0.05).MCA Vm decreased obviously after deepen anesthesia for 1,5,10 min (P＜0.05).The decrease in MAP,HR,PaCO2 and MCAVm is positively correlated with the decrease in SctO2.Conclusion:The decrease of MAP,HR,PaCO2,and MCAVm is the risk factor for SctO2.To avoid the decrease,it needs to maintain the stability of SctO2 and prevent neurological complications.