The antidiabetic effect of Amomum xanthioides(A. xanthioides) extract was investigated. Alloxan caused the hyperglycemia and hypoinsulinemia by a selective destruction of pancreatic ${eta}$-cell. Pretreatment of mouse with A. xanthiodies extract for 2 days prior to alloxan administration completely protected hyperglycemia induced by alloxan. In addition, administration of A. xanthioides extract to alloxan-induced diabetic mouse significantly abolished hyperglycemia, hypoinsulinemia, and, the reduction of size and number of insulin-secreting cells induced by alloxan. Administration of A. xanthioides extract to alloxan-induced diabetic mouse rapidly increased pancreatic Reg gene expression to 7 days, and then decreased. In alloxan-diabetic mouse. Reg gene expression was increased at 3 days after alloxan injection, and sustained until 24 days. The present results indicate that A. xanthioides extract contains potentially effective components exhibiting both protection and treatment of alloxan-induced diabetes. These results suggested that the antidiabetic effect of A. xanthoides extract may be mediated through the regeneration of pancreatic ${eta}$-cells.