目的：了解胃癌Ｋ－ｒａｓ基因突变情况及意义。方法；病理确诊的胃癌组织６０例，蛋白酶Ｋ法裂解，ＰＣＲ法扩增Ｋ－ｒａｓ基因密码子１２。结果：胃癌组织Ｋ－ｒａｓ基因突变率８．３３％，但胃上１／３部位的胃癌组织中，Ｋ－ｒａｓ基因突变率（２１．０５％）比胃其余部位显著高（Ｐ＜０．０５）。结论：Ｋ－ｒａｓ基因突变与否对胃癌的诊治、预后未见明显相关，突变率与病灶所处部位相关可能反映癌变的机理不同。 Objective: To understand the mutation and significance of K-ras gene mutation in gastric cancer. Methods: 60 cases of pathologically confirmed gastric cancer tissues were lysed by the proteinase K method and the K-ras gene codon 12 was amplified by PCR. RESULTS: The mutation rate of K-ras gene in gastric cancer tissues was 8.33%, but the K-ras gene mutation rate (21.05%) was significantly higher in gastric 1/3 gastric tissue than in the rest of the stomach (P<0. 05). Conclusion: There is no significant correlation between the diagnosis and treatment of gastric cancer and the prognosis of K-ras gene mutation. The relationship between the mutation rate and the location of the lesion may reflect the mechanism of canceration.