In vitro digestibility, prebiotic activity and chemical composition of polysaccharides from rapeseed were deliberately studied in this paper. After preliminary treatments, two fractions of polysaccharides (RP1 and RP2) were obtained after purification by DEAE-cellulose and Sephadex G-100. Their primary structural feature and molecule weights were characterized. Furthermore, their digestibility was also evaluated by artificial gastric juice and