Abstract: Objective:To investigate the anti-aging activity of carboxymethyl chitosan in Caenorhabditis elegans. Method:The lifespan,locomotion behavior,swallowing frequency and defecation cycle of C. elegans before and after treatment with carboxymethyl chitosan were detected. Moreover,the superoxide dismutase(SOD),catalase(CAT)and glutathione peroxidase(GSH-Px)of C. elegans were detected. Result:500,1000 mg/L carboxymethyl chitosan could significantly(P<0.05,P<0.01)prolong the life of caenorhabditis elegans,while 500 mg/L could significantly(P<0.01)improve the movement of Caenorhabditis elegans,accelerate the movement of pharyngeal pump,shorten the excretion period. At the same time,100,500 and 1000 mg/L carboxymethyl chitosan could significantly increase the activity of catalase and glutathione peroxidase in caenorhabditis elegans(P<0.01). Conclusion:500 mg/L carboxymethyl chitosan has a significant anti-aging effect and has application prospects of anti-oxidation and anti-aging.