Abstract: Ginseng polysaccharide (GPS) was obtained from ginseng, a traditional Chinese medicinal material, through an efficient extraction method in this work. Namely, the extracts of ginseng were first collected by ultrasonic assisted extraction of hot water, then purified through enzymolysis to remove the starch and protein, and finally refined by DEAE-52 cellulose column chromatography to get the desired ginseng polysaccharide (GPS-1). The molecular weight, monosaccharide composition and structure of GPS-1 were determined by high performance gel permeation chromatography, infrared spectroscopy and nuclear magnetic resonance spectroscopy. In addition, the role of GPS-1 in human skin fibroblasts (HFF-1) survival rate and the effect on reactive oxygen species (ROS), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), metalloproteinase 1 (MMP-1) and metalloproteinase 9 (MMP-9) were studied. The results showed that GPS-1 was a homogeneous polysaccharide with a purity of 95.13% and an average molecular weight of 2.104 kDa, which was composed of α-D-glucose, α-D-galacturonic acid, α-D-arabinose, α-D-fucose, α-D-ribose, β-D-mannose and β-D-arabinose. Moreover, the cell experiments confirmed that GPS-1 could protect HFF-1 cells from UVB irradiation, and the expression of MMP-1 and MMP-9 could be significantly inhibited by GPS-1 solution at the concentration of 200 μg/mL (P<0.01). Further study revealed that GPS-1 could also significantly increase SOD and GSH-Px content (P<0.01) and decrease the contents of ROS and MDA (P<0.01). These results would provide a scientific basis for the isolation and purification of ginseng polysaccharide and its application in the development of anti-aging products.