Abstract: In this study,RABPL2、RABPL1、RABPT and RABPF from different parts of Rhododendron aganniphum Balf.f.et K.Ward were extracted with ultrasonic method.The in vitro antioxidant activities of the four crude polysaccharides were investigated by determining the scavenging effects on·OH.O·2,·DPPH,and chelating effects on Fe2+ and reducing ability.The results showed that all of crude polysaccharides had significant effects on scavenging ·OH,O·2,·DPPH,and obvious Fe2+ chelating and reducing ability,the in vitro antioxidant activity of RABPL2 was higher than that of other three polysaccharides,and there was a doseeffect relationship was obviously.RABPL2 is kinds of excellent natural antioxidant and free radical scavenger,and have extensive development prospect.

Key words: Rhododendron aganniphum, polysaccharides, antioxidant activity