用套式聚合酶链式反应—单链构象多态分析法对３０例结肠癌的ｐ５３基因突变进行了观察，检测了第５～８四个外显子，发现２１例有ｐ５３基因突变（７０％）。３０例肠癌按临床Ｄｕｋｅｓ分期：Ａ期２例皆有突变，Ｂ期１１例有突变者６例（５５％），Ｃ期８例有突变者５例（６３％），Ｄ期９例有突变者８例（８９％），按病理分型则１３例有１１例突变（８５％），管状腺癌６例有ｐ５３基因突变４例（６７％），低分化腺癌５例中检出３例有突变（６０％），在６例粘液腺癌中测出３例有突变（５０％）。从临床分期看愈晚突变率愈高。而病理分型恶性程度高者突变率反低，这是因为缺失率未计数之故。最后讨论了突变率与预后的关系 Using nested polymerase chain reaction-single strand conformation polymorphism analysis, 30 cases of p53 gene mutations in colon cancer were observed. Five to eight exons were detected, and 21 cases were found to have p53 mutations (70). %). According to the clinical Dukes staging of 30 cases of colorectal cancer, there were 2 cases in stage A, 6 cases (55%) in stage B in 11 cases, 5 cases (63%) in 8 cases in stage C, and 9 cases in stage D. Eight cases (89%) were mutated, 11 cases were mutated (85%) in 13 cases by pathological type, 6 cases had p53 gene mutation in 4 cases (67%), and poorly differentiated adenocarcinoma was detected in 5 cases. Three cases had mutations (60%) and 3 cases (50%) were detected in 6 cases of mucinous adenocarcinoma. The later the mutation rate is higher from the clinical stage. The higher the malignancy of pathological type, the lower the mutation rate is, because the absence rate is not counted. Finally, the relationship between mutation rate and prognosis was discussed.