The extracellular matrix(ECM) maintains the structural integrity of the skin. Skin aging is associated with the degradation of the ECM by matix metalloproteinases(MMPs) and reduced cellular response to signals. Here, we investigated the effect of DermaPepTM A440, a newly developed tetrapeptide, on MMPs expression with or without UV-stimulation. Retinoic acid and TGF-b were used as positive controls. Our results demonstrate that DermaPepTM A440 significantly inhibited both UV-stimulated and unstimulated expression and production of MMPs and the inhibition was even greater than retinoic acid or TGF-b.