Solid and hollow CoO nanospheres were synthesized by solvothermal method with oleic acid as reactant and SiO2 as template. Each sample of high-purity CoO was characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron energy spectroscopy, respectively. Both solid and hollow CoO nanospheres as anode for lithium-ion battery were tested by galvanostatic discharge-charge experiments. The first discharge capacity of 1598 and 1640 mAh g(-1) was obtained at 0.1C for solid and hollow CoO nanospheres, respectively. Hollow CoO nanospheres showed better cycle performance.