Introduction: Infants and children after cardiac surgery may develop hyper- or hypoglycemia, associating with higher nosocomial infection or neurological morbidities. Hypothesis: The hypothesis of this perspective randomized control study is moderate glucose control may improve clinical outcomes. Methods: We randomly assigned children(≤3 years of age) who were admitted to the pediatric cardiac intensive care unit (PICU) after cardiopulmonary bypass surgery into either moderate glucose control group (target blood glucose: 110-143mg per deciliter) or conventional glucose control group (target level below 200mg per deciliter). The primary outcome was the rate of nosocomial infection in PICU. Second outcomes include hospital mortality, duration of mechanical ventilation and PICU stay, and a composite morbidity variable included events of requiring extracorporeal membrane oxygenation, delayed sternal closure, dialysis-dependent renal failure and hypoglycemia. Results: A total of 593 patients underwent randomization: 293 to moderate glucose control group and 300 to conventional glucose control group. The baseline data were balanced between these two groups. Mean 72 hours time-weighted blood glucose average was lower in the moderate control group than in the conventional group (129.9±22.1 mg per deciliter vs. 138.8±28.6 mg per deciliter, p<0.001). Although no statistically significance reached, there is a trend that nosocomial infection occurred less in moderate glucose group (17 (5.80%) vs. 29 (9.67%), P=0.054). Duration of mechanical ventilation was shorter in the moderate control group (18 (range, 4-300) hours vs 22 (range 3-771) hours, p=0.046). Hypoglycaemia (blood glucose ≤65mg per deciliter) which occurred in 7(2.39%) patients in the moderate group versus 8 (2.67%) in the conventional group, was statistically similar between groups. Other secondary outcomes did not differ significantly between groups. Conclusions: With moderate glucose control, although the major clinical outcomes did not change, this randomized control study showed shorter ventilation time after pediatric cardiac surgery, substantially benefit for patients with complex congenital cardiac anomalies.