To study the chemical constituents from the root of Polygala tenuifolia.Silica gel,Sephadex LH-20 and ODS chromatographic techniques were used to study the chemical constituents of Polygala tenuifolia, and the chemical structures were elucidated by application of spectral data.Eight-compounds were obtained and their structure were identified as 7-hydroxy-1-methoxy-2,3-methylenedioxyxanthone(1), 1, 7-dihydroxy-2, 3-dimethoxyxanth one(2), 1,3,6-trihydroxy-2, 7-dimethoxyxanthone(3),7-hydroxy-1,2, 3-trimethoxyxanthone(4), 1,2,3,6, 7-pentamethoxyxanthone(5), 1,3, 7-trihydroxy-2, 6-dimethanoxyxanthone (6),7-hydroxy-1-methoxyxanthone(7) and 1,7-dihydroxy-3,4-dimethoxyxanthone(8).Compounds 1,6,7 and 8 are isolated from Polygala tenuifolia for the first time.