Abstract The fresh roots of Pueraria Lobata were extracted with cool CH 3OH. The extract was concentrated and partitioned between CH 3COOC 2H 5 and water. Then the water phase was partitioned into n -BuoH. At last,the residue of organic phase was hydrolyzed by HCl,so the isoflavonoid hydrolyses precipitated from the hydrolysate. The isoflavonoid hydrolyses was chromatographyed on silica gel and four isoflavonoids were isolated. They were identified as 1) formononetin,2) daidzein,3) 3��-methoxy puerarin and 4) puerarin by TLC and spectra methods.