Acanthopanax senticosus is a typical food medicine homology in China. The antioxidant and anti-aging activities of A. senticosus polysaccharides, especially the purified polysaccharide, have not been thoroughly investigated. In the previous work, we purified a polysaccharide CQ-1 with hepatoprotective activity from A. senticosus with an average molecular weight (Mw) of 14,263 Da. In this study, Caenorhabditis elegans was used to investigate the antioxidant and anti-aging effects of CQ-1. We found that 0.4 and 0.8 mg/mL of the polysaccharide CQ-1 could prolong the average life span of the nematodes. Administration of 0.8 mg/mL CQ-1 was observed to significantly reduce the accumulation of lipofuscin in the worms, thereby delaying the onset of senescence. When oxidative stress was stimulated, CQ-1 was able to prolong survival by approximately 20 %. CQ-1 increased the activity of the antioxidant enzymes SOD and CAT and reduced the level of MDA. RT-qPCR analysis showed that the expression of the antioxidant gene sod-3 and the longevity-regulated gene daf-16 was significantly increased in polysaccharide-treated worms. Our result suggests that feeding CQ-1 is effective in extending lifespan in C. elegans by improving resistance to oxidative stress, which has great potential for development as an anti-aging food and drug.