Abstract: The polystyrene (PS) microspheres which were prepared by dispersion polymerization method were served as a template, the precursor PS-Gd (OH) CO₃ composite microspheres were prepared by homogeneous precipitation technique. The Gd₂O₃ hollow microspheres were obtained after the polymer microsphere templates were removed through calcinations. Low frequency and high damping Gd₂O₃/butyl rubber composites were prepared by blending Gd₂O₃ hollow microspheres with butyl rubber. FTIR, SEM, TEM, TG analysis, XRD and XPS were employed to characterize the structure and morphology of the Gd₂O₃ hollow microspheres. Gd₂O₃/butyl rubber composites were prepared by adding Gd₂O₃ hollow microspheres and powder as fillers to the butyl rubber separately. The results show that Gd₂O₃ hollow microspheres were composed of cubic fluorite structure with 0.9 μm outer diameter and about 100 nm shell thickness. The damping properties of composite with Gd₂O₃ hollow microspheres are better than that with Gd₂O₃ powder. Low frequency damping property of Gd₂O₃/butyl rubber composite has improved significantly compared with that of pure butyl rubber.