Abstract: Objective 　To study the expression of COX-2 in human renal cell carcinoma (hRCC) and it s relation to invasion and metastasis of RCC. Methods 　The expression of COX-2 and MMP-2 in primary RCCs specimens were detected by immunohistochemical technique. Results 　There was no or weak expression in non-carcinomatous speciment s of renal. Overexpression of COX-2 in renal cell carcinomas was related to it s pathologic grading, clinical staging and histological type ( P < 0. 01 ) ; The expression of MMP-2 in normal renal tissue was negative. The expression of MMP-2 was related to the pathologic grading and histological type ( P < 0. 01), But the expression of MMP-2 was not related to clinical staging ( P > 0. 05) . The correlation was found between COX-2 and MMP-2. Conclusion 　The overexpression of COX-2 in renal cell carcinoma may play a crucial role in its pathologic grading, clinical staging, histological type, invasion and metastasis in renal cell carcinoma, indicating that COX-2 may provide a target for chemotherapy strategy for renal cell carcinoma.