The chemical constituents of the roots of Angelica dahurica var. formosana were studied by using various chromatographic techniques, and their structures were established on the basis of NMR spectra.Eighteen non-coumarins were isolated and identified from the roots of Angelica dahurica var. formosana, including liquiritigenin (1), naringenin (2), hesperetin (3), naringenin 7-O-neohesperidoside (4), hesperetin 7-O-β-D-glucopyranoside (5), naringin (6), neohesperidin (7), narirutin (8), 3-hydroxy-5,6,7,8,3′,4′-hexamethoxyflavone 3-O-β-D-glucoside (9), secoisolariciresinol (10), pinoresinol monomethy ether-β-D-glucopyranoside (11), phillyrin (12), arctiin (13), (-)-pinoresinol-4-O-β-D-glucopyranoside (14), desmodimine (15), 1-H-imidazo ［4, 5-d］ pyridazin-2-amine (16), caffeic acid ethyl ester (17), caffeic acid methyl ester (18).All compounds were isolated from the roots of Angelica dahurica var. formosana for the first time except desmodinine (15).Compounds 3 and 18 inhibit the release of superoxide from neutrophils induced by zymosan with IC₅₀ values of 77.8±2.4 μmol/L and 44.7±13.5 μmol/L, respectively.Compounds 1 and 18 showed inhibitory activity anginst the nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells with IC₅₀ values of 44.7±4.1 μmol/L and 94.5±1.9 μmol/L, respectively.