The effect of fermented mushroom of Coprinus comatus rich in vanadium (CCRV) on glycaemic metabolism was studied in this paper. Alloxan-induced hyperglycemic mice were used in this study. The insulin secretion and glycogen synthesis of the mice were analyzed. At the same time, the gluconeogenesis of the normal mice was also determined. The alloxan-damaged pancreatic beta-cells of the mice were also studied in this paper. After the mice were administered (i.g.) with CCRV, the level of insulin secretion and glycogen synthesis of alloxan-induced hyperglycemic mice elevated (p<0.05, p<0.01) and the gluconeogenesis of the normal mice was inhibited (p<0.01). Also, the alloxan-damaged pancreatic beta-cells of the mice were partly recovered gradually after the mice were administered (i.g.) with CCRV 15 days later. These may account for the causes of CCRV-induced significant decreases of the blood glucose in hyperglycemic mice.