A CONTROLLED-RELEASE COMPOSITION AND CONTROLLED-RELEASE MICROSPHERES CONTAINING AN EXENDIN AS AN ACTIVE INGREDIENT, AND A METHOD OF PREPARING THE SAME ARE PROVIDED. MORE SPECIFICALLY, A CONTROLLED-RELEASE COMPOSITION CONTAINING AN EXENDIN AS AN ACTIVE INGREDIENT, A BIODEGRADABLE POLYMER WITH A SPECIFIC VISCOSITY, AND COATING MATERIALS, HAVING HIGH BIOAVAILABILITY AND SHOWING SUSTAINED RELEASE OF THE ACTIVE INGREDIENT IN AN EFFECTIVE CONCENTRATION FOR A CERTAIN PERIOD WITHOUT AN EXCESSIVE INITIAL BURST OF THE ACTIVE INGREDIENT； CONTROLLED-RELEASE MICROSPHERES CONTAINING A CORE INCLUDING AN EXENDIN AS AN ACTIVE INGREDIENT AND A BIODEGRADABLE POLYMER, AND A COATING LAYER COATING THE CORE； AND A METHOD OF PREPARING CONTROLLED-RELEASE MICROSPHERES INCLUDING THE STEPS OF MIXING AN EXENDIN, A BIODEGRADABLE POLYMER, AND A SOLVENT, REMOVING THE SOLVENT FROM THE MIXTURE TO PREPARE HARDENED MICROSPHERES, AND COATING THE HARDENED MICROSPHERES TO FORM A COATING LAYER ON THE SURFACE OF EACH MICROSPHERE, ARE PROVIDED.
