Objective To study the influence of vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) on invasion and metastasis of human colorectal carcinoma. Methods VEGF expression was detected by SABC immunohistochemical method and the new growth microvessels were highlighted by SP immunohistochemical staining of CD34 endothelial antigen in 61 colorected carcinoma tissues, and the MVD of tumor tissues was calculated. Results The positive expression rate of VEGF was 49 2% and the average MVD was 28 7?12 9 in colorectal carcinoma tissues. The VEGF expression and MVD in colorectal carcinoma tissues were significantly associated with the depth of invasion, lymph node metastasis, liver metastasis and Dukes' stage (P