Objective: To study on separation and purification feasible process of polysaccharides from R. palmatum by ultrafiltration. Method: Centrifugation conditions were optimized by orthogonal test before ultrafiltration

ultrafiltration technology parameters were optimized by uniform design with yield and concent of polysaccharides as indexes

and ultrafiltration pressure

liquid temperature and liquid concentration were selected as investigated factors. Result: Optimum ultra-filtration process was:centrifuged 12 min with 3 000 r · min-1

membrane with 105 molecular interception

ultrafiltration pressure 0.05-0.09 MPa

liquid temperature 40℃

ratio of solid-liquid 1: 10-1: 30

pH 6.0

ultrafiltration membrane was pretreated 10 min with tween-80 (5 g ·L-1). Conclusion: Optimized ultrafiltration process could obtain higher yield and concent of polysaccharides while compared with non-ultrafiltration. Ultrafiltration technology could be used for purification and enrichment of polysaccharides from R. palmatum with industrial development prospect.