目的　探讨Ｐ１６ 蛋白在大肠癌发生发展中的作用及其意义．方法　应用免疫组织化学方法检测５６ 例大肠癌，１５ 例正常结肠组织中Ｐ１６ 蛋白的表达情况，并分析其意义．结果　大肠癌组织中阳性率（３３－８ ％ ） 低于正常对照结肠组织中的阳性率（７３－３ ％ ） ，差异非常显著（ Ｐ＜ ０－０１） ．Ｐ１６ 蛋白的表达与肿瘤分化程度及Ｄｕｋｅｓ 分期相关（ Ｐ＜ ０－０５） ．结论　Ｐ１６ 蛋白在大肠癌的发生发展中起重要作用，反映肿瘤恶性程度和肿瘤进展情况． Objective To investigate the role and significance of P16 protein in the development of colorectal cancer. Methods Immunohistochemical method was used to detect the expression of P16 protein in 56 cases of colorectal carcinoma and 15 cases of normal colon tissue, and its significance was analyzed. Results The positive rate of colorectal carcinoma (33-8 %) was lower than that of normal control colon tissue (73-3 %), and the difference was very significant (P < 0-01). The expression of P16 protein correlated with tumor differentiation and Dukes stage (P< 0-05). Conclusion P16 protein plays an important role in the development of colorectal cancer, reflecting the degree of malignancy and tumor progression.