Abstract: Twenty compounds were isolated from the ethyl acetate extract of Smilax glabra by using various chromatographic techniques, including macroreticular resin, silica gel, Sephadex LH-20 and semi-preparative HPLC. Their structures were elucidated by physicochemical properties, MS and spectroscopic data. These compounds were elucidated as glabraside A (1), glabraone A (2), 5-hydroxy-3ʹ,4ʹ,7-trimethoxy-flavanone (3), naringenin (4), quercetin 7-O-α-L-rhamnoside (5), neoastilbin (6), neoisoastilbin (7), isoastilbin (8), eriodictyol-7-O-β-D-glucopyranoside (9), naringenin-7-O-α-L-rhamnoside (10), kaempferol 3-O-4'''''-O-acetyl-α-L-rhamnosyl-(1→6)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (11), 5-hydroxymaltol (12), 3,4,5-trimethoxyphenyl-1-O-β-D-glucopyranoside (13), 2-(3',4'-dihydroxyphenyl)-1,3-benzodioxole-5-aldehyde (14), kompasinol A (15), (+)-syringaresinol (16), cis-resveratrol (17), trans-resveratrol (18), flufuran (19) and 5-hydroxymethyl-furaldehyde (20). Two new compounds (1 and 2) showed inhibitory activity toward nitric oxide (NO) production, with IC₅₀ values of 56.8 and 29.5 μmol·L^-1, respectively.