The expression of p53 protein in 66 cases of colorectal cancer and its relationship to cell porliferative activity, lymph node metastasis as well as prognosis were investigated by means of AB-PAP immunohistochemieal technique. The results showed that 62.1% of colorectal cancer was positive of p53 expression. The cell proliferative activity and the frequency of lymph node metastasis in p53- positive tumors were significantly higher than those in p53-negative tumors (P<0.05). The survival rate in patients with p53- positive tumors was significantly poorer than those with p53- negative tumors (P<0.05). Our results suggest that the abnormal expression of p53 and cell proliferation associated with mutations are involved in both human carcinogenesis and lymph node metastasis of coloreetal cancer. Examination of p53 expression is of value in understanding the degree of malignancy, and evaluating prognosis of the disease.