Disclosed is a chalcone composition for treating diabetes and metabolic syndromes. In particular, the chalcone compound bound with 2-halogen in ring A significantly decreases the blood glucose level in the in vitro anti-diabetic effect experiment. In the in vivo animal model, the leading chalcone compound can prevent the progression of diabetes and control the blood glucose level, and there is no significant difference in the gains in body weight. Throughout the seven-week administration, there are no hepatic or renal toxicity observed.