A kind of novel pitch-based activated carbon microsphere(ACM) characterized by its controlled porous structure was developed in this study,the curative effect of this ACM on diabetes mellitus in rats was investigated.ACM 0.2-0.3 mm in diameter was prepared by modified method.The optimal ACM was screened by its adsorption ability for glucose.Diabetes mellitus model was established by streptozotocin injection in male Sprague-Dawley rats.Two groups of rats were orally administrated with ACM twice a day for 30 d.Intestinal glucose transport was determined in vitro using everted rat intestinal sacs technique.Compared with the diabetic mellitus group,the ACM treated group showed significant lower blood glucose level and improved glucose tolerance after two-week treatment.If ACM was applied in the mucosal side,glucose permeation clearance in the ACM treated group was significantly higher than that of the control group,especially at high glucose concentration(10 mg/mL) on the serosal side.The selected ACM possessed a BET specific surface of 1566 m^2/g and high volume of micropores(0.478 cm^3/g) with fine spherical morphology,and showed more significant adsorption capacity for glucose.As oral microsphere preparations,ACM presented the curative effect on streptozotocin-induced diabetes mellitus in rats.