Abstract: The present invention relates to a surface-treated cathode active material for an aqueous lithium secondary battery, and more particularly, to a surface-treated cathode active material in which deterioration of the surface structure of an active material caused by side reactions between an aqueous electrolyte solution and the active material may be prevented by uniformly coating a predetermined amount of a stabilization material (for example, AlF3) onto the surface of the cathode active material (for example, LiMn2O4) for a lithium secondary battery using an aqueous electrolyte, such that the cycle properties (cycle stability and cycle lifetime), rate capability, and output properties of an aqueous lithium secondary battery are greatly enhanced, to a method for preparing the same, and to a cathode and aqueous secondary battery including the same.