Abstract: The isolated and purified conditions of soybean isoflavones were studied by contrast examination. Fat, protein andthe other impurity from the ethanol extracts could be cleaned elementarily by combining isoelectric precipitation, centrifugaltionat 2000rpm and ultrafiltration (PLHK 100000). The impurity such as sugars could be eluted by distilled water from themacroporous adsorption resin column and the isoflavones could be eluted by 50%~70% ethanol. Results showed that the yieldof isoflavones was more than 85%, the purification degree in the produce was over 65%.

Key words: Soybean isoflavones , Extraction , Purification