1目的　探讨 P5 3蛋白在胃癌组织中表达的意义。 2方法　应用免疫组织化学技术和原位杂交技术 ,检测 45例胃癌及 2 1例胃溃疡组织中 P5 3蛋白的表达。 3结果　 P5 3蛋白在胃溃疡组织中无表达 ,在胃癌组织中表达阳性率为 33.3% ,两者比较差异有极显著性 (χ2 =8.0 3,P<0 .0 1)。 4结论　 P5 3蛋白在胃癌发生中可能起重要作用 Objective To investigate the significance of P53 protein expression in gastric cancer. 2 Methods Immunohistochemistry and in situ hybridization were used to detect the expression of P53 protein in 45 cases of gastric cancer and 21 cases of gastric ulcer. 3 Results P53 protein was not expressed in gastric ulcer tissues, and the positive rate was 33.3% in gastric cancer tissues. There was a significant difference between the two groups (χ2=8.03, P<0.01). 4 Conclusion P53 protein may play an important role in gastric carcinogenesis