Bioassay-guided fractionation of the MeOH extract of the whole plant of Geum japonicum led to the isolation of seven known tannins. They were identified by spectroscopic methods as penta-O-galloyl-beta-glucoside (1), pedunculagin (2), 2, 3-(S)-hexahydroxydiphenoyl-D-glucose (3), tellimagrandin II