Objective: To investigate the relationship between the expression of Raf-1 and tumor angiogenesis,and to discuss its clinical significance.Methods: Tissue microarray technique was used to detect the expression of Raf-1 in 87 specimens of human colon carcinoma,their corresponding adjacent tissues,and incision margins.The patients were from the Department of Pathology of Xijing Hospital between 2005 and 2006.Microvessel density(MVD) was detected using immunohistochemistry with CD34 labeling.The correlation between Raf-1 expression and MVD with the tumor size,metastasis,and differentiation was analyzed.Results: The positive rates of Raf-1 in colon carcinoma tissues,adjacent tissues and incision margins were 86.47%,37.34% and 11.03%,respectively;there were significant difference among the 3 values(P