AIM: To investigate the expression and significance of matrix metalloproteinase-2(MMP-2) and tissue inhibitor of metalloproteinase-2(TIMP-2) in the rat traumatic cataract models. METHODS:Twenty healthy SD rats(weighing 250-300g) were used to establish traumatic cataract model on left eyes and then divided into post-traumatic 12, 24, 72 and 168 hours groups randomly. The expression of MMP-2 and TIMP-2 in lens epithelial cells(LEC) were examined by immunohistochemistry staining. RESULTS: In the post-traumatic 12 hours, lens opacity began to appear and aggravated as the time went by. Immunohistochemical results showed positive MMP-2 expression in the LEC of every traumatic groups. No expression of MMP-2 was detected in the compared eyes without surgery. But there was no statistical significance for TIMP-2 expression (P>0.05). There was no correlation between the expression of MMP-2 and TIMP-2 (P>0.05). CONCLUSION: MMP-2 takes part in the formation process of traumatic cataract. The imbalance between the expression of MMP-2 and TIMP-2 may play a critical role in the generation and development of traumatic cataract.