Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) play pivotal roles in the degradation and remodeling of the extracellular matrix (ECM). The cooperation and balanced expressions of MMPs and TIMPs are essential issues for the cyclic growth, differentiation, maintenance, and degradation of the tissues during physiologic and pathologic processes. Transforming growth factor-β (TGF-β) could perform its biological effect on ECM by regulating the gene expressions of MMPs and TIMPs. The different modulating effects of TGF-β on MMPs and TIMPs in different cell types are due to the activating of Smad pathway, MAPK signaling pathway or inducing the formation of AP-1 complex by extracellular TGF-β signal.