Abstract: Biodegradable poly(hydroxybutyrate-hydroxyvalerate)-poly(lactide-co-glycolide) (PHBV-PLGA) microspheres with gentamicin-loading were prepared and characterized by solid-oil-oil-water method. The diameter of the microspheres with spherical or ellipsoidal shape ranges in 20-80 μm and the encapsulation efficiency of gentamicin sulfate is more than 60%. The cumulative rate of drug-release reaches 100% in 16-20 d. In addition, the degradation properties are investigated. The cumulative drug release is about 50% in 90 d in phosphate buffer solution.