代谢酶多态性决定着机体对外源化学物的易感性和耐受性，也是肿瘤发生的遗传易感影响因素之一。本文报道了胃癌病人中Ｎ－乙酰化酶多态性的调研。３４例胃癌病人中１３例为慢型（３８２４％）；对照组１０７人中２０人为慢型（１８６９％）。基因频率分别０６１８３和０４３２３，两者之间有显著差异（Ｐ＝０．０２２）。从中推算出乙酰化酶慢型者患胃癌的相对危险度为２６９（１１６～６．２７），说明乙酰化酰慢型作为肿瘤遗传易感因素，在胃癌发病中的作用不应忽视。 Metabolic enzyme polymorphism determines the susceptibility and tolerability of exogenous chemicals in the body, and it is also one of the factors affecting genetic susceptibility to tumorigenesis. This article reports the investigation of N-acetyltransferase polymorphism in patients with gastric cancer. Of the 34 patients with gastric cancer, 13 (3824%) were slow-type patients; of the 107 patients in the control group, 20 (1869%) were slow-type. The gene frequencies were 06183 and 04323, respectively. There was a significant difference between the two (P=0.022). The relative risk of developing acetyl-acylase slow type in gastric cancer was calculated to be 269 (116–6.27), indicating that acetylated slow type is a genetic susceptibility factor in cancer and its role in the pathogenesis of gastric cancer should not be Ignore.