Aim To explore the relation between insulin resistance (IR) and deletion polymorphism of angiotensin converting enzyme(ACE)gene in patients with old myocardial infarction. Methods The insulin resistance was calculated by fast plasma insulin × fast plasma glucose÷22.5; The deletion (D)/insertion(I) polymorphism of the ACE gene was determined by polymerase chain reaction in 55 patients with old myocardial infarction and in47 control subjects. Results The insulin resistance level did not increase significantally in patients with old myocardial infarction, compared with control subjects(P>0.05); There were not significant difference of IR level among ACE DD、DI、Ⅱ gene types in the old myocardial infarction group(P>0.05 ). Conclusions The association of deletion polymorphism of ACE gene and IR with coronary heart disease were not found. The relation between deletion polymorphism of ACE gene and IR was also not identified in patients with coronary heart disease.