Matrix metalloproteinases (MMPs) are known to play an important role in photoaging by mediating the degradation of extracellular matrix proteins. In this study, to develop a n ew anti-aging agent, we investigated the antioxidant activity and the inhibitory effect of Melothria heterophylla extract on expression of MMP-1 in UVA-irradiated human dermal fibroblasts and MMP-1 activity. The M.heterophylla extract was found to scavenge radicals and reactive oxygen species (ROS) with the $SC_{50}$ values of $13{mu}g/ml$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and $20{mu}g/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. UVA-induced MMP-1 expression was reduced about 80% by $100{mu}g/ml$ of the M.heterophylla extract but MMP-1 Mrna expression was not inhibited. Therefore, we conclude that the M.heterophylla extract significantly inhibits MMP-1 expression at the protein level. Also, the M.heterophylla extract inhibited MMP-1 activity in a dose dependent manner. From these results, we suggest that the M.heterophylla extract can be used as a new anti-aging agent by antioxidant activity, regulation of UVA-induced MMP-1 production, and inhibition of MMP-1 activity.