Objective:To study the expression changes of matrix metal loproteinases (MMPs) in traumatic deep vein thrombosis (TDVT) in a rat model with the aid of gene chip technology and to explore the roles of MMPs in TDVT.Methods:Totally 150 Sprague Dawley rats were randomly divided into control group (n=10) and model group (n=140). Rat models of TDVT were established by clamping the femoral vein and fixing the bilateral hind limbs. Then fixation of the hip spica with plaster bandage was conducted.According to the observation phases and/or biological situations of the femoral vein thrombosis, the model rats were further divided into 7 groups. Vascular tissues were obtained from each group through noninvasive incision into the femoral vein at corresponding time points. We adopted the Trizoi one-step method for total RNA extraction,Affymetrix RAT 230 2.0 array for detection of RNA expressions and fold change (FC) analysis for changes of differential expressions of MMPs in each group. The main outcome parameters measured included expressions of MMP-2,MMP-3, MMP-7, MMP-8, MMP-9, MMP-10, MMP-11,MMP- 12, MMP-13, MMP- 14, MMP- 16, MMP-23 and MMP-24. Gene array data of these MMPs were analyzed by the Affymetrix Microarray Analysis software (Version 5.0).Results:FC analysis showed differential expressions of MMPs in each group during the course of TDVT. At the initial period of thrombosis, MMP-2, MMP-3, MMP-7,MMP-8, MMP-9, MMP- 10, MMP-11, and MMP-24 had significantly high expression, while MMP-12, MMP-13,MMP-14, MMP-16 and MMP-23 had relatively low expression. MMPs were all highly expressed at the peak time of thrombosis. In the process of thrombus resolution,MMP-2, MMP-10, MMP-16 and MMP-24 have relatively low expression, while MMP-12, MMP-13, MMP-14,MMP-16 and MMP-23 have significantly high expression.Conclusion:MMPs may affect the process of TDVT through transcription regulation of the fibrinolysis-anti-fibrinolytic system during the course of thrombosis and thrombus resolution.