Abstract: The present study examined the effects of crude Polysaccharide from Gynostemma pentaphyllum (PGP) against oxidative stress induced by swimming exercise. Male rats were administered PGP (50, 100, 200 and 400 mg kg-1) by gavage every day. After 30 days, swimming exercise of rat was performed in acrylic plastic pool. The results showed that PGP treatment prolonged exhaustive swimming time and improved liver glycogen reserve which suggested that PGP treatment influenced the performance of exhaustive exercise and improved exercise tolerance. Moreover, PGP treatment can promote increases in the activities of Super Oxide Dismutase (SOD), Catalase (CAT) and Glutathione Peroxidase (GPH-Px) and reduce lipid per-oxidation which suggest that PGP treatment was beneficial in enhancing the antioxidant status and inhibiting oxidative stress induced by exhaustive exercise.