A method was established for the identification and quantification of Daidzein,Genistein,Formononetin and Biochanin A in the extracts from Trifolium pratense with the reversed-phase liquid chromatography with an ultraviolet-diode array detector. The column was DiamonsilTM C18 column,250×4.6 mm and 5 μm particle. The solvent A was CH3CN; solvent B,0.1 % H3PO4,and the percentage of solvent A increased linearly,after an initial hold of 1 min,from 15 % to100 % in 60 min. The detection was by absorbance at 260 n...