Abstract: Disclosed is a metal gradient-doped cathode material for lithium ion batteries including a hexagonal-crystalline material body and a modifying metal. The metal gradient-doped cathode material is formed by coating modifying metal hydroxide on the surface of the hexagonal-crystalline material using a chemical co-precipitation method, then sintering the modifying metal hydroxide coated hexagonal-crystalline material. The modifying metal is different from the active metals, more concentrated on the surface, and gradually decreases toward the core of particle. A gradient-doped distribution is formed without any boundary or layered structure in the particle. The surface of the powder with more the modifying metal can effectively reduce the reactivity of the cathode material with the electrolyte in the lithium battery.