Objectives To explore whether the angiotensin Ι-converting enzyme(ACE) I/D(insertion/deletion) polymorphism is associated with the susceptibility to high altitude pulmonary edema(HAPE) in the Han Chinese. Methods One hundred and forty-seven HAPE-p(HAPE patients) and 193 HAPE-r(HAPE resistants) were enrolled from the Yushu earthquake reconstruction workers in Qinghai province where the altitude is over 3 500 m above sea level. Blood samples were collected from each of the HAPE-p and HAPE-r groups. Information about physiological phenotypes was obtained via fieldwork investigation. The ACE-I/D polymorphism in HAPE-p and HAPE-r was detected by polymerase chain reaction(PCR). Results The SaO2 was significantly lower while HR was significant1y higher in HAPE-p group than those in HAPE-r group. The genotype frequencies of ACE-I/D for II, ID, DD in HAPE-r and HAPE-p groups were 0.430, 0.446, 0.124 and 0.435, 0.469, 0.095, respectively, the allelic frequencies of I and D were 0.650, 0.350 and 0.670, 0.330, respectively. The OR of ID, DD and D alleles relative to II for HAPE was 0.961(0.610~1.514), 1.322(0.634~2.758) and 1.080(0.783~1.489). There was no significant difference of the genotypic and the allelic frequencies in ACE-I/D polymorphism between HAPE-p and HAPE-r groups. Conclusions There is no relation between ACE-I/D polymorphism and HAPE in the Han Chinese. Objectives To explore whether the angiotensin Ι-converting enzyme (ACE) I / D (insertion / deletion) polymorphism is associated with the susceptibility to high altitude pulmonary edema (HAPE) in the Han Chinese. Methods One hundred and forty-seven HAPE-p (HAPE patients) and 193 HAPE-r (HAPE resistants) were enrolled from the Yushu earthquake reconstruction workers in Qinghai province where the altitude is over 3 500 m above sea level. Blood samples were collected from each of the HAPE-p and HAPE- The groups of information about physiological phenotypes were obtained via fieldwork investigation. The ACE-I / D polymorphism in HAPE-p and HAPE-r was detected by polymerase chain reaction (PCR). Results The SaO2 was significantly lower while HR was significant1y higher in The genotype frequencies of ACE-I / D for II, ID, DD in HAPE-r and HAPE-p groups were 0.430, 0.446, 0.124 and 0.435, 0.469, 0.095, respectively , the allelic frequencies of I and D were 0.650, 0.350 and 0.670, 0.330, respectively. The OR of ID, DD and D alleles relative to II for HAPE was 0.961 (0.610 ~ 1.514), 1.322 (0.634 ~ 2.758) and 1.080 (0.783 ~ 1.489). There was no significant difference of the genotypic and the allelic frequencies in ACE-I / D polymorphism between HAPE-p and HAPE-r groups. Conclusions There is no relation between ACE-I / D polymorphism and HAPE in the Han Chinese.