The polysaccharide of Camellia Nitidissima Chi was extracted by water extraction and alcohol precipitation, and the polysaccharide was purified by DEAE cellulose anion exchange classification to obtain TPS1, TPS2 and TPS3;The molecular weight, monosaccharide composition and microstructure of TPS1, TPS2 and TPS3 were analyzed by gel permeation chromatography, pre-column PMP derivatization and HPLC and fourier transform infraredspectrometer （FTIR）, and the antioxidant activity of TPS1, TPS2 and TPS3 were studied in vitro. The results were described as followed. TPS1 was mainly composed of glucose, galactose and arabinose, and was a heteropolysaccharide composed of two polysaccharides with different molecular weights（1.55×10⁵, 1.05×10⁴ Da）.TPS2 and TPS3 were mainly composed of rhamnose, galacturonic acid, galactose and arabinose, and they were homogeneous polysaccharides with the average molecular weight of 4.21×10⁵ Da and 6.67×10⁵ Da, respec-tively. Fourier transform infrared spectrometer （FTIR） showed that the heterocarbon-connected modes of three polysaccharide fractions were β-configuration. In addition, the polysaccharides of different levels of Camellia Nitidissima Chi had certain free radical scavenging effects, and there was a dose-effect relationship. Among them, TPS3 with the highest content of uronic acid had the best antioxidant activity in vitro, indicating that the antioxidant activity of Camellia Nitidissima Chi polysaccharide was related to its structural and composition. In conclusion, the polysaccharide of Camellia Nitidissima Chi had potential antioxidant activity.