There is provided a lithium secondary battery having a high capacity and excellent high-rate discharge characteristic and charge/discharge cycle characteristic. The lithium secondary battery comprises a negative electrode, a positive electrode and an ionic conductor, wherein the positive electrode comprises lithium metal composite oxide particles; the lithium metal composite oxide particles comprise a plurality of secondary particles in an elongated shape each comprised of a plurality of primary particles with an average particle size of 0.1 to 1 μm so aggregated as to form a void therebetween; and the secondary particle is columnar or planar and has an average size in a long length direction of 5 to 15 μm.