In Korea and China, Ulmus davidiana var. japonica has been used as a traditional oriental medicine for the treatment of difficulty in urination, skin inflammation, etc. In order to investigate the potential of a polysaccharide extract from Ulmus davidiana var. japonica as a cosmetic ingredient, we measured its moisturizing effect, photo-induced cytotoxicity, and anti-inflammatory effect. After hydrolysis, HPLC experiments showed that the composition of the polysaccharide extract was mainly rhamnose, galactose, and glucose. The molecular weight of the obtained Ulmus davidiana root extract was 20,000. The intrinsic viscosity was 90 dl/g. In a moisturizing test conducted through the measurement of water loss in a desiccator and of moisture content with a Corneometer CM820, Ulmus davidiana root extract showed almost the same moisturizing effect as hyaluronic acid. In an assay for inhibition of the H(2)O(2)-activated release of PGE2, IL-6, and IL-8 in normal human fibroblast cell lines, Ulmus davidiana root extract showed an inhibitory activity of PGE2 release in a dose-dependent manner (up to 85.9% at a concentration of 0.1%). The percent inhibition of the release of IL-6 was in the range of 45.6% to 64.5% (H(2)O(2) was used as the positive control). Moreover, the release of IL-8 was completely inhibited in the entire concentration range (>0.0025%). In a test of recovery from photo-induced damage after UVA irradiation (3 J/cm(2)), the cell recovery of human fibroblasts increased to levels two times higher than that of the positive control, which was UVA-damaged cells in the absence of Ulmus davidiana root extract (up to 60.2% at 3.0% of Ulmus davidiana root extract). In a photo-induced cytotoxicity assay in the presence of promethazine as a photosensitizer, Ulmus davidiana root extract showed approximately 48% of the increased cell viability of the control. Therefore, Ulmus davidiana root extract may be useful for the development of a cosmetic ingredient.