目的：了解高原低氧分压对新生儿染色体畸变的影响。方法：收集新生儿脐带血（高原１６例，对照组５０例）常规培养、制片、Ｇ式显带、计数观察。结果：（１）高原组１６例新生儿中，染色体结构发生改变１０例，占６２５％，明显高于对照组１６０％（８／５０）（Ｐ＜０．０１）。（２）高原组新生儿染色体计数观察１５９４个，发生畸变８３个，占５２０７％；对照组共计数观察５００２个，发生畸变９４个，占１８７９％，两组比较有极高度显著性差异（Ｐ＜０．０１）。（３）高原组新生儿染色体结构异常占２１３３％（３４／１５９４），其中内复制６个，双微体１４个，碎片断１０个，着丝粒爆开１个，断裂或增加３个，明显高于对照组０４２％（２１／５００２）（Ｐ＜０．０１）。（４）高原新生儿染色体数目异常占３０７％（４９／１５９４），明显高于对照组１４５９％（７３／５００２）（Ｐ＜０．０１）。结论：高原新生儿染色体畸变率增加可能与高原低氧分压有关。 Objective: To understand the effect of plateau hypoxia on neonatal chromosomal aberrations. Methods: Neonatal umbilical cord blood (plateau 16 cases, control group 50 cases) routine culture, production, G-banding, counting observations. Results: (1) Among 16 newborns in plateau group, chromosome structure changed in 10 cases (625%), which was significantly higher than that in control group (160%, 850) (P <0.01). (2) The number of neonatal chromosomes in plateau group was 1594, 83 of them were aberration (5207%). In the control group, there were 5002 total chromosomes with aberration of 94 (1879%). There were extremely significant differences between the two groups Sex differences (P <0.01). (3) The chromosomal abnormalities accounted for 2133% (34/1594) in neonates in plateau group, among which 6 were duplicated, 14 were double microdomains, 10 were fragmented, 1 was broken by centromere, 3 was broken or increased by 3 Which was significantly higher than that in the control group (042%, 21/5002) (P <0.01). (4) The number of chromosome abnormalities in plateau was 307% (49/1594), which was significantly higher than that in control group (1.459%, 73/5002) (P <0.01). Conclusion: The increase of chromosome aberration rate in plateau newborn may be related to the hypoxia pressure in plateau.