Background：Most cardiac surgeries with cardiopulmonary bypass (CPB) in children need transfusions of packed red blood cells (PRBCs), but the risks and benefits of transfusions remain controversial. There are still few studies on the outcome of transfusion or not during CPB in children with bodyweights of 8-17kg undergoing cardiac surgery, so we aim to investigate the effects of PRBCs transfusions during CPB. Methods: A total of 155 children with bodyweights of 8-17kg undergoing uncomplicated congenital heart surgery with CPB were divided into the non-transfusion group (group A, n=60) and transfusion group (group B, n=95) according to whether they were transfused perioperatively. By using a propensity score matching method, 55 patients were ultimately included in each group. The perioperative hematological test results and recovery of patients were compared by the independent sample t-tests or the chi-squares tests. Postoperative follow-up information within 0.5 to 2.5 years was also collected. Results: Hb before CPB was higher in group A than in group B (p<0.05). There were no differences in Hb during CPB or before hospital discharge, except that the Hb on the first day after surgery was lower in group A than in group B (p<0.05). There were no differences in the hematological test results, postoperative recovery or follow-up outcomes between the two groups. Conclusions: Non-transfusion CPB does not affect the Hb concentrations before hospital discharge, the postoperative recovery or short-term follow-up outcomes in children with bodyweights of 8-17kg undergoing uncomplicated congenital heart surgery, indicating these children can avoid transfusions.