Through studies of xanthones from Polygla tenuifolia, one of the main medicinal plants of Polygala, the structural characteristics and spectroscopic rules (including IR, UV, (1)H NMR and (13)C NMR data) of xanthones from Polygala were summarized, combined with the reference reports of this type of compounds from the other plants of Polygala. It is helpful to the structure elucidation of xanthones.