To study the chemical constituents of Paeonia lactiflora flowers.[corrected] The chemical constituents were isolated and purified by various chromatography methods,and the structures were identified by physicochemical and modem spectroscopic.11 compounds were identified as gallic acid(1),methyl gallate(2),ethyl gallate(3),1,2,3,6-tetragalloyl-beta-D-glucopyranoside(4), 1,2,3,4,6-pentagalloyl-beta-D-glucopyranoside(5), quercetin-3-O-glucoside-6"-gallate(6), kaempferol-3-O-glucoside-6"-gallate(7), 1-O-galloyl-beta-D-glucose (8), kaempferol-3, 7-di-O-beta-D-glucoside(9), paeoniflorin(10) and albiflorin(11).Compounds 1-8, 10 and 11 are obtained from the flowers of Paeonia lactiflora for the first time,compounds 6 and 7 are obtained from Paeonia genus for the first time.