Defatted rice bran was hydrolyzed by amylase, glucoamylase and pepsin to remove starch and protein. Then the rice bran polysaccharides were extracted from the treated defatted rice bran under acidic conditions and basic conditions once respectively. The result showed that defatted rice bran was mixed with distilled water with the ratio of 1∶15 g/mL. The mixture was hydrolyzed by 3% α-amylase for 2 h, 3% glucoamylase for 1 h and 3% pepsin for 1 h to remove starch and protein, extracted for 90 min in acidic and alkaline environments once respectively with ultra-sonic condition as 70 ℃, 200 W. The yield of the rice bran polysaccharides was 8.12%. After freeze-drying, the crude polysaccharides contained 84.2% rice bran polysaccharides, 6.6% crude protein, 2.1% ash and 5.8% water.