Abstract: To explore the extraction and content of isoflavone aglycones in Seme Sojae Preparatum, soybean and black soybean, ultrosonic wave was used in the experiments. Besides, soybean isoflavone glucosides were transformed to aglycones by β- glucosidase. Soybean isoflavones in different materials were identified by the method of polyam ide TLC, while quantified by HPLC. The experiments results indicated that genistin, daidzein and genistein could be separated perfectly within twenty minutes under the mobile phase of methanol:aceticacid:water (12:1:10). The content of isoflavone aglycones was the most in Seme sojae Preparatum, and black soybean had the lest content. The precision RSD were 1.45 % and 1.6 % respectively, and the average recovery was 100.93 %, which proved that the method of experiments was both veracious and credible.

Key words: ultrosonic extraction, polyam ide, hydrolyze, genistein, daidzein, HPLC