Objective:The aim of the study was to investigate the expressions of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of MMP-2 (TIMP-2) mRNA in transitional cell carcinomas of bladder and discuss their clinical significances.Methods:Using RT-PCR and real time quantitative PCR (RQ-PCR) technique, the expressions of MMP-2 and TIMP-2 mRNA of 45 cases of bladder carcinoma (tumor group) and 10 cases of normal bladder tissue (control group) were analyzed. Results:MMP-2 and TIMP-2 were not expressed in control group. MMP-2 was expressed in 30 cases tumor samples and TIMP2 was expressed in 26 cases. The expression of MMP-2 mRNA in non-muscle invasive bladder cancers and grade I cancers significant (P < 0.05). The expression of MMP-2 in recurrent patients was higher than that in incipient patients. TIMP-2 mRNA expression decreased with grades and stage. The expression of TIMP-2 in non-muscle invasive bladder cancers and statistical difference between two groups (P 0.05). Conclusion:These results suggest that MMP-2 and TIMP-2 play an important role in the invasion step of transitional cell carcinoma of bladder. MMP-2 may become a new approach to the diagnosis of bladder carcinoma.