Objective   To study the expressions and correlation of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) in human transitional cell carcinoma of bladder (TCC) tissues and explore the correlation of their expressions in the incidence and development of TCC.    Methods   The expressions of COX-2 and EGFR were detected by immunohistochemical technique in 48 cases of TCC and in 10 cases of normal bladder mucosa tissues.    Results   The expressions of COX-2 and EGFR in TCC was significantly higher than those in normal bladder mucosa tissues (P0.01)

and the positive expression rates of COX-2 and EGFR was 70.8% and 66.7% respectively. The abnormal expressions of COX-2 and EGFR were related to the tumor grade

clinical stage and recurrence (P0.05). The expression of COX-2 positively correlated with that of EGFR (Kappa=0.419， P=0.004).    Conclusion   COX-2 and EGFR are commonly coexpressed in bladder tissues of TCC

and their expressions is closely correlated. Both of them may play an important role in the tumorigenesis and tumor progression in TCC. Therefore

the coexpression of COX-2 and EGFR seems to be regarded as a tumor marker for patients with TCC and can be used to evaluate the tumor biological behavior and prognosis.