目的：了解ｐ５３基因杂合性丢失与胃癌发生、发展的关系。方法：应用位于１７ｐ１３区域的ｐ５３ｃＤＮＡ探针和ｐＹＮＺ２２ＶＮＴＲ探针，对胃癌及癌旁正常组织基因组ＤＮＡ进行Ｓｏｕｔｈｅｒｎ杂交。结果：在２２例胃癌中，１２例正常组织被检出有杂合性，其中６例标本癌组织发生了杂合性丢失，检出率为５０％。结论：ｐ５３基因杂合性丢失是胃癌发生过程中一种常发事件 Objective: To understand the relationship between the loss of heterozygosity of p53 gene and the occurrence and development of gastric cancer. Methods: The p53 cDNA probe and pYNZ22VNTR probe located in the 17p13 region were used for Southern blotting of the genomic DNA of gastric cancer and adjacent normal tissues. RESULTS: Among the 22 cases of gastric cancer, heterozygosity was detected in 12 cases of normal tissues, of which 6 cases had loss of heterozygosity and the detection rate was 50%. Conclusion: Loss of heterozygosity of p53 gene is a common event in gastric carcinogenesis