To investigate the relationship between the expression of cyclooxygenase-2 (COX-2), and invasive depth and angiogenesis in human transitional cell carcinoma (TCC), the expression of COX-2 and von Willebrand factor (vWF) was detected in paraffin-embedded transitional cell carcinoma specimens from 50 patients with histologically confirmed bladder transitional cell carcinoma. Microvessels were counted and microvessel density (MVD) was calculated. The correlation between COX-2 and invasive depth, MVD and invasive depth, COX-2 and MVD were analyzed. COX-2 expression was significantly related to the invasive depth of tumors; it solely expressed in invasive TCC. The ratio of COX-2 positively stained samples in each stage correlated to the invasive stages; so did the proportion of COX-2 (+) cells in whole tumor cells. Also, MVD increased with the invasive stages of tumors and positively correlated to the invasive depth. The COX-2-positive TCC samples were highly vascular, their microvessel density was significantly higher than that of the COX-2-negative TCC samples. There was a positive correlation between MVD and COX-2 (+) cells proportion. Our findings suggested that COX-2 was positively correlated with the invasive depth and involved in the process of angiogenesis in human transitional cell carcinoma.