Tumor cell metastasis is a process of extracellular matrix hydrolyzed by protease, where tumor cells traverse the defect in the extracellular matrix into the lymphatic system and the capillaries to form new metastasis hematogenously.Matrix metalloproteinases (MMPs) are a kind of enzymes closely related to the metastasis.MMP, especially the relationship between MMP-9 and endometrial cancer metastasis in this paper will be summarized to get a better understanding about it.