To explore the distribution of I/D polymorphisms of angiotensin converting enzyme (ACE) gene and its relation to natural longevity in the Xinjiang Uygur people. Polymerize chain reaction, single strand conformation polymorphism, and direct sequencing technique were used to test the I/D polymorphisms of ACE gene in 42 centenarians, 102 people aged 90-99, 70 people aged 65-70, 53 cases of natural death aged 65-70 were used as controls. The frequencies of ACE genotypes DD, DI, and II were 28.6%, 30.9%, and 40.5% respectively in the centenarian group, the frequency rates of D and I alleles were 0.44 and 0.56. The frequency rate of D/D genotype of the centenarian group was significantly higher than that of the group aged 65-70 (28.6% vs. 12.9%, chi2 = 4.25, P < 0.05), however, not significantly different from that of the group aged 90 (P > 0.05). The frequency rate of D allele of the group of centenarian was significantly higher than that of the group aged 65-70 (44.0% vs. 36.4%, chi2 = 4.47, P < 0.05). The frequency rates of genotype D/D and D alleles were significantly higher in the centenarian group than in the controls (both P < 0.01). ACE gene polymorphism is closely correlated with life span of individuals. Longevity is the result of pleiotropic age-dependent influence of multiple factors.