Abstract: Lithium cobaltate （LiCoO<SUB>2</SUB>） which is used in lithium-ion battery as cathode material can not be used widely in the field of high-power and-capacity batteries because of its high cost,limited raw material,serious pollution,toxicity as well as its insecurity of over-charging.Cobalt-doped lithium nickelate &nbsp;（LiCo<SUB>x</SUB>Ni<SUB>1-x</SUB>O<SUB>2</SUB>） &nbsp;has been treated as ideal material in replacing lithium cobaltate as cathode material of lithium-ion battery because of its high discharge capacity,low cost,and pollution-free etc..Preparation method,problems,and solutions of cobalt-doped lithium nickelate as cathode material of lithium-ion battery were summarized.Meanwhile,a brief forecast for the future development tendency of LiCo<SUB>x</SUB>Ni<SUB>1-x</SUB>O<SUB>2</SUB> as cathode material of lithium-ion battery was also made. 