Abstract: Objective To investigate the expression of MMP-2 and TIMP-2 mRNA in transitional cell carcinoma of bladder and discuss their clinical significance.Methods Using RT-PCR and real time quantitative PCR(RQ-PCR)technique,the expression 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 TIMP-2 was expressed in 26 cases.The expression of MMP-2 mRNA in superficial bladder cancer and G1 cancer were lower than that in infiltrating bladder cancer and G2-G3 cancer respectively.The differences were statistically significant(P ＜0.05).The expression of MMP-2 in recurrence group was higher than that in incipient group.TIMP-2 mRNA expression decreased with grades and stage.The expression of TIMP-2 in superficial bladder cancer and G1 cancer were higher than that in infiltrating bladder cancer and G2-G3 cancer respectively.There was statistical difference between two groups(P ＜0.05).TIMP-2 expression in incipient group was higher than that in recurrence group,but the difference was not significant(P＞0.05).Conclusion These results suggest that MMP-2 and TIMP-2 play an important role in the invasive step of transitional cell carcinoma of bladder.MMP-2 may become a new approach to the diagnosis of bladder carcinomas.