We previously reported that the extract of Taraxacum platycarpum (AF-343) had several biological properties such as skin hydration and anti-inflammatory effects, thereby AF-343 be a promising anti-atopic dermatitis agent. However, few studies have been conducted to evaluate its effect on modulation of extracellular matrix proteins in human skin fibroblasts. The purpose of this study was to investigate the expressions of type I collagen, MMP-1, Smad2/3, and TIMP-1 proteins in AF-343-treated human skin fibroblasts. Human skin fibroblasts were treated by various concentrations of AF-343 (0~2 mg/ml). The expressions of type I collagen, matrix metalloproteinase-1 (MMP-1), Smad2/3, and TIMP-1 proteins were analyzed by Western blot analysis. In addition, level of type I collagen mRNA was analyzed by CAT assay. Expression of type I collagen protein was increased in AF-343-treated human skin fibroblasts by dose and time-dependent manners. Consistent with this result, the expressions of phospho-Smad2/3 in skin fibroblasts were increased and MMP-1 expression was decreased by AF-343 treatment. TIMP-1 expression was not significantly changed in AF-343 treated skin fibroblasts. Extract of Taraxacum platycarpum (AF-343)-induced up-regulation of type I collagen expression was through increased expression of phospho-Smad2/3. These results were occurred combined with down-regulation of MMP-1 in skin fibroblasts. Taken together, this study indicated that AF-343 has property of the modulation of ECM in tissue as well as skin hydration and anti-inflammation.