Abstract: HPLC was used for separation and determination of four isoflavone compounds (biochanin A, formononetin,genistein, and daidzein) in different parts (leaf, flower, and stem) of Trifolium pratense. The results showed that there weredifferent distributions of the examined isoflavone compounds among different plant organs. The contents (dry weight) of totalfour isoflavone compounds in the leaf, stem and flower of Trifolium pratense were 0.856%, 0.403%, and 0.258%, respectively,among which the highest was in the leaf and the lowest in the flower. Biochanin A and formononetin were two kinds ofpredominant isoflavones in Trifolium pratense. The content (dry weight) of biochanin A in different parts was in a range from0.077% to 0.358%, among which the highest was in the leaf and the lowest in the stem. The content of formononetin in differentparts was in a range from 0.106% to 0.437%, among which the highest was in the leaf and the lowest in the flower. However, theamount of genistein and daidzein in different parts was low, whose content (dry weight) varied from 0.013% to 0.044%.

Key words: isoflavones, Trifolium pratense, HPLC