Matrix metalloproteinases (MMPs) are a family of calcium-dependent, zinc-containing endoproteinases capable of degrading the extracellular matrix and basement membrane. Many inflammatory stimuli, such as wound healing, ultraviolet, hyperosmolarity, and stress, can stimulate production of inflammatory cytokines and a variety of MMPs, including gelatinases, collagenases, and stromelysins. Pro-inflammatory cytokines and growth factors can further promote the production of MMPs. Thus, MMPs participate in and promote the inflammation process. MMP-9 may be a most important amplifying factor for corneal inflammation. Mitogen activated protein kinases are involved in MMPs amplified inflammation. These pathway studies provide new therapeutic potential to block MMP mediated inflammation.