Abstract: Ultrasonic method extraction was used to extract the eleocharis tuberosa peel polyphenols. And the suitable extract conditions was obtained by single factor experiments and orthogonal test,then inhibitory action of eleocharis tuberosa peel polyphenol crude extraction on linoleic acid lipid peroxidation system was studied. The results showed that extractant was 60 % ethanol, pH 3.5, feed liquid ratio was 1∶30 (W/V), ultrasonic time was 50 min, on these conditions, eleocharis tuberosa peel polyphenols yield was 1.8 %, and have strong lipid antioxidant activity.

Key words: eleocharis tuberosa peel, ultrasonic method, polyphenols, lipid antioxidant activity