Abstract: Objective To investigate the expression of HER-2/neu protein in human colon cancer tissues and its relationship with clinical pathology. Methods Immunohistochemistry was used to detect the expression of HER-2/neu protein in 79 specimens of human colon cancer tissues and adjacent tissues. Results The expression rate of HER-2/neu in the cancer tissues was significantly higher than that in the adjacent tissues (P<0.05), and the positive expression rate of HER-2/neu was significantly higher in Dukes stages C and D and those with lymph node metastasis than in Dukes stages A and B and those without lymph node metastasis (P<0.05). Conclusions HER-2/neu is expressed in part of colon cancer tissues, suggesting that HER-2/neu can be used as a marker for the diagnosis and prognosis of colon cancer.