A facile two-step annealing process is applied to synthesize nanocage Co
3O 4, using cobalt-based metal-organic framework as precursor and template. The as-obtained nanocages are composed of numerous Co 3O 4nanoparticles. N 2adsorption-desorption isotherms show that the as-obtained Co 3O 4has a porous structure with a favorable surface area of 110.6 m2 g-1. Electrochemical tests show that nanocage Co 3O 4is a potential candidate as anode for lithium-ion batteries. A reversible specific capacity of 810 mAh g-1 was obtained after 100 cycles at a high specific current of 500 mA g-1. The material also displays good rate capability, with a reversible capacity of 1069, 1063, 850, and 720 mAh g-1 at specific current of 100, 200, 800, and 1000 mA g-1, respectively. The good electrochemical performance of nanocage Co 3O 4can be attributed to its unique hierarchical hollow structure, which is maintained during electrochemical cycling.