Objective   To detect the expressio n of p16 protein in colorectal cancer and its significance in clinical application.

  Methods   Immuno histo chemistry S-P was used to detect the p16 protein of colorectal cancer.

  Results   The positive rate of p16 protein was 75.7% in 37 cases, In high, mediate and low differentiated colorectal cancers was 87%, 17%, respectively, the positive rate (100%) in colonic tumor was higher than the recta's tumor, and then between them exist the evidence differences. In Dukes stage, the ABand CD positive rate was 81% and 69%, respectively. The lymph node without metastasis was higher (positive rate 81%) than the lymph node with metastasis's positive rate 69%.

  Conclusion   The p16 protein was associated with the occurrence and development of colorectal cancer, and the same as the histology classification, Dukes stages and whether metastasis of lymph node. The p16 protein can be considered the indication of nature cause of disease and prognosis of colorectal cancers in the future clinical applications.