目的　探讨血管紧张素转换酶 (ACE)基因多态性与中国汉族人脑梗死危险因素关系。方法　应用聚合酶链反应 (PCR) ,测定 16 5例脑梗死、10 1例高血压患者和 10 6例正常对照者ACE基因插入 /缺失 (I/D)多态性 ,用比色法测定血清ACE水平 ,并调查脑梗死经典的危险因素。结果　脑梗死组DD型基因频率为 0 .43,高于高血压组的 0 .31(χ2 =4.0 3,P <0 .0 5 )和正常对照组的 0 .17(χ2 =19 .86 ,P <0 .0 1) ,且D等位基因亦明显高于高血压组和正常对照组 (χ2 =7.14、32 .85 ,P <0 .0 1)。基底节、丘脑梗死者其DD型基因频率和D等位基因亦高于对照组 (χ2 =18.30、12 .41、2 9.0 0、12 .10 ,P <0 .0 1)。脑梗死组血清ACE水平明显高于正常对照组 (F =2 2 40 .0 6 ,P <0 .0 1) ,其中DD基因型血清ACE水平又高于同组DI基因和II基因 (F =8.83,P <0 .0 1)。结论　ACE基因缺失多态性可能是中国人汉族脑梗死独立危险因素 ,循环ACE活性与基因缺失多态性相关 Objective To investigate the relationship between angiotensin converting enzyme (ACE) gene polymorphisms and risk factors of cerebral infarction in Han Chinese. Methods Polymerase chain reaction (PCR) was used to detect ACE gene insertion / deletion (I / D) polymorphisms in 165 cases of cerebral infarction, 101 hypertensive patients and 106 healthy controls. Serum ACE levels and investigate classic risk factors for cerebral infarction. Results The frequency of DD gene in cerebral infarction group was 0.43, which was higher than that in hypertension group (P <0.05), and was significantly higher than that in hypertension group (P <0.05). The frequency of DD gene was 0.43 (χ2 = 19.86, P <0.01), and the D allele was also significantly higher than those in the hypertensive group and the normal control group (χ2 = 7.14, 32.85, P <0.01). The frequency and D allele of DD genotype in basal ganglia and thalamic infarct were also higher than those in control group (χ2 = 18.30,12 .41,2 9.00,12.10, P <0.01). The level of serum ACE in cerebral infarction group was significantly higher than that in normal control group (F = 2240.066, P <0.01), and the serum ACE level in DD genotype was higher than that in DI and II genes in the same group (F = 8.83, P <0.01). Conclusions ACE gene deletion polymorphism may be an independent risk factor for cerebral infarction in Chinese Han population. The correlation between circulating ACE activity and gene deletion polymorphism