Due to substantial morbidity and high complications, diabetes mellitus is considered as the third "killer" in the world. Medicinal fungal polysaccharides, as water-soluble macromolecular substances with low toxicity, exhibit diversified pharmacological actions such as immune regulation, anti-tumor, antivirus, antioxidant, anti-aging, hypoglycemic effect and improving liver and kidney function. In recent year, a number of investigators reported medicinal fungal polysaccharides showed good anti-diabetes and hypoglycemic activity, and their acting mechanisms involved in glycometabolism and β cell function, e. g. promoting glycogen synthesis, promoting glycolysis, inhibiting the activity of α-glucosidase, promoting insulin secretion, increasing insulin sensitivity, enhancing antioxidation. Therefore, the hypoglycemic activity and its mechanisms of action of medicinal fungal polysaccharides showed characteristics of multiple effects, multi-target, and multi-pathway regulation. These finding suggest that medicinal fungal polysaccharides are a promising source for the development of discovery of anti-diabetic agent.