A separator including: a porous polymer substrate having a plurality of pores; and a coating layer formed on at least one surface of the porous polymer substrate, and including a plurality of lithium-containing composite particles and a binder positioned on the whole or a part of the surface of the lithium-containing composite particles to connect and fix the lithium-containing composite particles with each other, wherein the lithium-containing composite particles includes a lithiated compound and a passivation film formed on the surface of the lithiated compound, and the passivation film includes a solid electrolyte interface (SEI). A lithium secondary battery including the separator and a method for manufacturing the lithium secondary battery are also provided.