Objective：To study  the expression of  TSPAN-1 and CORTACTIN protein in colorectal carcinoma, and investigate the relationship between the expression and clinicopathological parameters  of colorectal carcinoma.
Methods：Immunohistochemical  Elivision two-step method was used to detect the expression of TSPAN-1 and CORTACTIN protein in 80 cases of colorectal carcinoma,13 cases of  colorectal adenoma and 27 cases of normal colorectal tissues. 
Results：The positive expression rate of TSPAN-1 and CORTACTIN in colorectal carcinoma was significantly higher than that in colorectal adenoma  and normal colorectal tissues, and there was significant difference in expression of every group (P<0.01). The positive  expression rate of  TSPAN-1 and CORTACTIN was 90% and 97.5% in group colorectal carcinoma，23% and 77% in group colorectal adenoma and 7.4% and  52% in group normal colorectal tissues (P＜0.01). The expression of TSPAN-1 and CORTACTIN was positively related with lymph node metastasis,TNM stage,5-year survival rate,histopathological grading  and depth of tumor invasion  (P<0.01). The expression of TSPAN-1 was positively related with the expression of CORTACT  in colorectal carcinoma (r=0.397, P=0.013).
Conclusions：The over expression of TSPAN-1 and CORTACTIN  gene are closely related to the invasion and growth of colorectal carcinoma, and TSPAN-1 and CORTACTIN have synergistic effect on  infiltration, invasion and metastasis of malignant cells. Detecting the expression of  both TSPAN-1 and CORTACTIN may be of value in further understanding the biological behavior and predicting the prognosis of colorectal carcinoma.