Pyropia haitanensis polysaccharide (LP) have been found for having many excellent functions such as anti-aging. Using Caenorhabditis elegans models, we evaluated the anti-aging activity of LP by observing the lifespan, reproduction, pharyngeal pumping, stress response, quantitative fluorescence of polyglutamic acid, and nuclear localization of DAF-16 of worms. The results reveal that LP could extend the adult lifespan of wild-type and polyQ nematodes, indicating a connection of its anti-aging benefit with the toxicity-suppressing effect. The number of polyglutamic acid aggregates in high concentration groups decreased by 24.39% ( P <0.05) to the control. The high-dose group strongly induced DAF-16 nuclear translocation over intermediate and cytosolic localizations compared with the control ( P <0.001). Therefore, we believe that LP could extend the lifespan and reduce the protein aggregation in C. elegans through nuclear DAF-16??GFP expression.