The present invention relates to a method for preparing a superoxide-generating composition and a superoxide-generating composition prepared by the method. Specifically, the method comprises coating a shell having a calcium compound attached thereto on the surface of a core having a superoxide-generating composition attached thereto so that superoxide generated from the core can pass through the shell having the calcium compound attached thereto to extend the half-life of the superoxide to thereby delay the disappearance of the superoxide, and the superoxide-generating composition can naturally generate superoxide without having to use light irradiation or plasma.
