目的：评价体外循环下不阻断升主动脉行心内直视术对心肌的保护作用。方法：对１９９５年９月至１９９８年８月在先心心内直视术中应用此法的１３６例婴幼儿进行回顾性分析。全组男７７例，女５９例。年龄３个月～５岁（平均３６５±１２０岁），体重５～１８（平均１４０１±３５２）。病种包括室间隔缺损１０３例，房间隔缺损１２例，法乐氏四联症１４例，法三２例，肺动脉瓣狭窄２例，部分性房室管通道２例，三尖瓣下移１例。结果：全组死亡３例（２２％）。术后并发症：低心排２例，支气管痉挛３例，二次止血１例。结论：体外循环下不阻断升主动脉行心内直视术是临床效果满意，安全有效的心肌保护方法。 OBJECTIVE: To evaluate the protective effects of cardiopulmonary bypass with open heart surgery under cardiopulmonary bypass. Methods: A retrospective analysis was performed on 136 infants and young children who underwent this method from September 1995 to August 1998 in the open heart surgery. The whole group of 77 men and 59 women. They ranged in age from 3 months to 5 years (mean, 365 ± 120 years), and weighed 5-18 (mean 1401 ± 352). The disease included 103 cases of ventricular septal defect, 12 cases of atrial septal defect, 14 cases of tetralogy of Fallot, 2 cases of French, 2 cases of pulmonary valve stenosis, 2 cases of partial atrioventricular canal, tricuspid valve down 1 example. Results: All the patients died in 3 cases (22%). Postoperative complications: low cardiac output in 2 cases, bronchospasm in 3 cases, secondary hemostasis in 1 case. CONCLUSION: Cardiopulmonary protection without ascending aorta under cardiopulmonary bypass is a safe and effective method for myocardial protection.