Abstract: In order to explore the hypoglycemic activity of Enteromorpha intestinalis polysaccharide, the components were separated by DEAE cellulose column chromatography and their physical and chemical properties were determined, and the effect of EIP-2 components on hypoglycemic indexes in mice was studied. The experimental animals were divided into normal group, model group, metformin positive group (50 mg/kg/day), EIP-2 low dose group (50 mg/kg/day), EIP-2 medium dose group (100 mg/kg/day), EIP-2 high dose group (200 mg/kg/day). The body weight, fasting blood glucose concentration, glucose and insulin tolerance, serum insulin and lipid levels, liver antioxidant enzyme levels were measured. The results showed that compared with the model group, the weight of mice in each dose groups was significantly increased (P<0.001), fasting blood glucose was significantly decreased (P<0.001), glucose and insulin tolerance were improved after EIP-2 intervention. The levels of serum nonestesterified fatty acid in high dose group were significantly lower than those in model group (P<0.01), and the levels of serum insulin and triglyceride were decreased in a dose-dependent manner. Compared with the model group, the liver aspartate aminotransferase level was significantly decreased (P<0.01), alanine aminotransferase level was significantly decreased (P<0.001), superoxide dismutase level was significantly increased (P<0.01), and the liver catalase level was significantly increased in the low-dose group (P<0.05). In summary, EIP can improve blood glucose regulation, blood lipid metabolism and liver oxidative stress in T2DM mice, which provides a reference for study of the hypoglycemic mechanism of EIP and the development and utilization of hypoglycemic drugs.