Abstract: In order to study the structural characteristics and bioactivity of rose receptacle polysaccharide,the rose receptacle polysaccharide was isolated and purified into three fractions by DEAE-52 cellulose column chromatography. The structural analysis showed that rose receptacle polysaccharide was composed of glucose,arabinose,galactose,galacturonic acid,rhamnose,glucuronic acid,and mannose in a molar ratio of 24.01:14.57:11.50:9.77:5.5:1.09:1,and configuration was furanose. The results of in vitro antioxidant experiments showed that rose receptacle polysaccharide had a strong antioxidant capacity,and the EC₅₀ values of scavenging hydroxyl radical and scavenging DPPH radical were 699.46 mg/L and 514.31 mg/L,respectively. Through the comparative analysis,it could be seen that rose receptacle polysaccharide had similar structure to the rose petal polysaccharide. But the antioxidant activity of rose receptacle polysaccharide was slightly stronger than rose petal polysaccharide. Therefore,the rose receptacle polysaccharide was an excellent natural antioxidant,and it had the value of further development and utilization.