The present invention provides a positive electrode active material for lithium secondary batteries, comprising domain-oriented agglomerated particles, wherein each of the domain-oriented agglomerated particles comprises a plurality of individually oriented secondary particles such that adjacent secondary particles thereof have mutually different orientation directions, and wherein each of the individually oriented secondary particles is composed of a plurality of primary particles which are composed of a lithium complex oxide with a layered rock-salt structure and are oriented such that the (003) planes of the primary particles do not intersect each other at least in one axial direction. According to the present invention, a positive electrode active material can be provided that is capable of achieving not only high initial output performance but also a high output performance retention rate when charging and discharging are performed repeatedly.