BACKGROUND: During the screening of natural products for potential anti- diabetogenic components, a strong protective effect of Amomum xanthoides extract on alloxan-induced beta-cell damage and in a mice diabetic model. In this study, the therapeutic effect of Amomum xanthoides extract was investigated after induction of diabetes by alloxan. METHODS: Experimental diabetes was induced by the injection of alloxan (60 mg/kg) to the mouse via the tail vein. To examine the effect the of Amomum xanthoides extract on diabetes, Amomum xanthoides extract (2.5 mg/mouse) was admini- strated intraperitoneally. The effect of the Amomum xanthoides extract on alloxan- induced diabetes was observed by measuring the blood glucose and serum insulin level, and a histological examination. RESULTS: Alloxan caused hyperglycemia and hypoinsulinemia by a selectively destroying pancreatic beta-cell. Pretreating the with an Amomum xanthoides extract completely protected them from the hyperglycemia induced by alloxan. In addition, the Amomum xanthoides extract administe 3 days after the of alloxan injection significantly abolished the hyperglycemia and hypoinsulinemia induced by alloxan. the alloxan-treated mice showed a marked change of in the pancreatic islets: the number of islets was reduced and the size of the remaining islets also decreased. However these effects of alloxan were significantly recovered by a later administration of the Amomum xanthoides extract. CONCLUSION: The amomum xanthoides extract contains potentially effective components, which both protect and treat alloxan-induced diabetes. The identification and action mechanism of the effective components of the Amomum xanthoides extract requires further investigation and it is suggested that the Amomum xanthoides extract be used as a therapeutic drug for diabetes.