Abstract: Ten compounds were isolated and purified from ethanol extracts of dried roots bark of Polygala tenuifolia Willd. by various chromatography techniques such as silica gel and Sephadex LH-20. Their structures were identified by analysis of physicochemical properties and spectral data, and determined as β-sitosterol (1), tenuifolin (2), 6-methoxy coumarin (3), 7-phenyl-1-hydroxy-2, 3, 6-trimethoxyxanthone (4), 1, 8-dihydroxy-3, 4, 7-trimethoxyanthone (5), mangiferin (6), quercetin-3-O-β-D-glucoside (7), rutin (8), syringaldehyde (9), salicylicacid (10). Among them, compounds 3, 4 and 5 were isolated from the genus of Ploygala for the first time and compound 4 was a new xanthone. The acetylcholinesterase inhibitory activities of compounds 3, 4 and 5 were evaluated by Ellman colorimetric method, compounds 3 and 5 exhibited moderate inhibitory activity, compound 4 exhibited weak inhibitory activity.