The present invention relates to a copper foil current collector having superior adhesion to an active material of a Li secondary battery. The electrolytic copper foil of the present invention having a first surface and a second surface comprises: a first protective layer at the first surface; a second protective layer at the second surface; and a copper film between the first and second protective layers, wherein an oxygen-containing part at the second surface has a thickness (OT) of not less than 1.5 nm. According to the present invention, an electrolytic copper foil current collector for a Li secondary battery, which has low electric resistance and high adhesion to an active material, can be provided.