Abstract: The flavonoid was separated and purified from the crude extract of Lithocarpus polystachyus(Wall.) Rehd. leaves with macro-porous resin (MPR) ADS-7, and the technology conditions were investigated in this experiment. The results showed that the optimum condition of the technology was that the ratio of the crude extract solution/resin was a little bigger than 3, static adsorption time was 2 h at neutral pH value, 1 500 mL 80% (volume fraction) ethanol as eluant, and eluation speed was 500 mL/h. By this technology the flavonoid content was increased from 40% of the crude extract to 88% of the purified product and the yield was 91%.

Key words: macro-porous resin, Lithocarpus polystachyus(Wall. ) Rehd., flavonoid, purification