In this study, the ID genotype was more prevalent (59.3 vs. 30.2%, p<0.01), and the DD genotype (12.9 vs. 41.9%, p< 0.01) was less prevalent in Kawasaki group than in control group. And I allele was more prevalent in Kawasaki group than in control group. However, both genotype (DD, ID, II) and allelic frequencies were not statistically different between Kawasaki disease patients with coronary dilatations and those without. Therefore, ACE gene I/D polymorphism was thought to be associated with the prevalence of Kawasaki disease but not with the development of coronary lesions. These results are similar to the report by Wu et al. (13) that the DD genotype was present in lower frequency among Kawasaki patients and ACE polymorphism was not associated with coronary aneurysmal formation. These results are different from the study by Takeuchi et al. (27) that the II genotype of ACE gene is more prevalent in Kawasaki disease and those with coronary aneurysm. These inconsistent results may be accounted for different ethnic traits of the individual population.