A nonaqueous secondary battery is provided, which comprises a positive electrode, a negative electrode and a nonaqueous ion conductor, the negative electrode containing a lithium-containing substance or a lithium insertable and releasable substance as a positive electrode active material, the positive electrode containing a lithium nickelate compound as a positive electrode substance, wherein the lithium nickelate compound has a layered rocksalt crystalline structure belonging to Space Group R-3m and the ratio of a 3a- and 3b-site occupation rate of lithium atoms to a 3a- and 3b-site occupation rate of nickel atoms in the crystal lattice thereof is 0.85 to 1.15.