Objective To explore the correlation between central venous oxygen saturation(ScvO2)-re-lated indexes at different time points and the occurrence of low cardiac output syndrome(LCOS)after con-genital heart disease(CHD)correction surgery.Methods A total of 73 children who underwent CHD correc-tion surgery in this hospital from July 1st,2021 to July 1st,2024 were selected as the research subjects.The clinical data,preoperative conditions,and postoperative conditions of the children were collected.The ScvO2 and arterial lactate(Lac)levels of the children at different time points(the 1st,6th,12th,and 24th hours after surgery)were monitored,and the ScvO2/Lac at different time points and the change rate of ScvO2 in different time periods were calculated.The correlation between ScvO2-related indexes and LCOS after CHD correction surgery was analyzed.Results ScvO2 at the 6th hour after surgery,ScvO2 at the 12th hour after surgery,Sc-vO2/Lac at the 12th hour after surgery,the change rate of ScvO2 from the 1st to the 24th hour after surgery,the change rate of ScvO2 from the 6th to the 12th hour after surgery,and the change rate of ScvO2 from the 12th to the 24th hour after surgery were independent influencing factors of LCOS occurrence after CHD cor-rection surgery(P＜0.05).There was a negative correlation between ScvO2 at the 12th hour after surgery,ScvO2/Lac and LCOS occurrence after CHD correction surgery(r=-0.543,-0.523,P＜0.05).The area under the curve(AUC)of ScvO2 at the 12th hour after surgery for predicting LCOS occurrence after CHD correction surgery was 0.938(95％CI:0.865-1.000);the AUC of ScvO2/Lac at the 12th hour after surgery for predicting LCOS occurrence after CHD correction surgery was 0.922(95％CI:0.851-0.994).Conclusion ScvO2 and ScvO2/Lac at the 12th hour after surgery have good predictive potential for LCOS occurrence af-ter CHD correction surgery.