Background: It has been reported that the recently developed intermittent antegrade warm blood cardioplegia (IAWBC) has better myocardial protective effects during coronary artery bypass surgery than cold blood cardioplegia or continuos retrograde cold blood cardioplegia. The aim of this study is to evaluate the safety and usefulness of IAWBC by comparing it retrospectively with intermittent retrograde cold blood cardioplegia (lRCBC). Material and Method: From April 2001 to Feb. 2003, fifty seven patients who underwent isolated coronary surgery were divided into two groups (IAWBC vs. IRCBC). The two group had similar demographic and angiographic characteristics. There were no statistical differences in age, sex, Canadian Cardiovascular Society Functional Classification for angina, ejection fraction, and number of grafts. Result: Aortic cross clamping time and total pump time in IAWBC (99$pm$23 and vs. 126$pm$32 min) were shorter than those of IRCBC (118$pm$32 min. and 185$pm$48 min.)(p<0.05). The reperfusion time (13$pm$7 min) in IAWBC was shorter than that of IRCBC (62$pm$109 min.)(p<0.05). CKMB at 12 hours and 24 hours (16$pm$15 and 9$pm$13) in IAWBC was lower than that of IRCBC (33$pm$47 and 17$pm$26)(p<0.05). The awakening time in IAWBC (2$pm$1 hour) was shorter than that of IRCBC (4$pm$3)(p<0.05). The number of spontaneous heart beat recovery in IAWBC (85%) was more than that of IRCBC (35%)(p<0.05). The cardiac index after discontinuing cardio-pulmonary bypass was significantly elevated in the IAWBC group. The prevalence of perioperative myocardial infarction in IAWBC (4%) was lower than that of IRCBC group (20%)(p<0.05). Conclusion: Intermittent antegrade warm blood cardioplegia is a safe, reliable, and effective technique for myocardial protection. It can also provide simpler and economic way than the retrograde cold cardioplegia by shortening of cardiopulmonary bypass time and avoiding retrograde cannulation for coronary sinus.