Objective To investigate the relationship between tumor invasion and changes of mRNA expression of MMP-2, TIMP-2 and CD147 in human pituitary adenoma. Methods 60 patients with pituitary adenoma were devided into two groups, invasive and non-invasive group, by MRI. The expression level of MMP-2,TIMP-2 and CD147 in the samples of pituitary adenoma was measured by semiquantitative reverse transcriptasepolymerase chain reaction (RT-PCR). Pearson analysis was used to reveal the correlation between the expression of each marker. Results The mRNA expression level of MMP-2 and CD147 was significantly higher in invasive pituitary adenoma group than that in non-invasive group (P ＜ 0. 01 ) while the mRNA expression level of TIMP-2was lower in invasive pituitary adenoma group than that in non-invasive group (P ＜0.01 ). According to Pearson analysis, the mRNA expression of MMP-2 was positively correlated with CD147 in invasive pituitary adenoma (r=0. 69, P ＜ 0. 05 ), and M MP-2 was negatively correlated with TIMP-2 in non-invasive pituitary adenoma (r =-0.68, P ＜ 0.05 ). Conclusions The invasion of human pituitary adenoma are closely related to the low expression level of TIMP-2 as well as the high expression level of MMP-2 and CD147. MMP-2, TIMP-2 and CD147 can be used as indicators of tumor invasion of human pituitary adenoma.