Objectives: In this study, a polymer micelle containing berberine (Ber) was prepared. The micelle was composed of Pluronic F127 and Ber. The hypoglycemic effect was verified by animal experiments.Methods: The Ber-loaded micelles were prepared with a thin-film hydration method. Encapsulation efficiency, surface morphology, particle size, zeta potential, differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were determined. The drug release profile of Ber was studied with the dialysis method. In addition, the streptozocin (STZ)-induced type 2 diabetic model in mice was used to examine the hypoglycemic effect.Key Findings: The average size of the prepared micelles was 91.1 nm with a polydispersity of 0.285. Compared with the Ber ethanol solution, the in vitro release of Ber from micelles presented the sustained-release property. The animal experiments verified the micelles increased body weight and decreased food and water intake of type 2 diabetic mice. Also, the level of blood glycosylated hemoglobin (GHb), total cholesterol (TC), total triglyceride (TG), and non-esterified fatty (NEFA) was lowered, from which we inferred that the Ber-F127 micelles had the expected hypoglycemic effect.Conclusions: Our results suggested that F127 micelles might serve as a promising nanocarrier to improve the solubility and bioavailability of Ber.