The goal of the present invention is to provide substances to prevent diseases by activating inherently possessed functions, for cultured fishes and shellfishes and livestock with tendency of decreased immune function due to densely populated breeding environment, and for humans with tendency of easily lowered immune functions due to complicated social structures and aging. The present invention expresses marked effect in preventing infection and cancer by administrating appropriate dose of swine plasma, swine plasma albumin, peptides isolated from swine plasma and swine plasma albumin, and swine plasma mixture, among others including fine powder of Crustacea (including crust of Crustacea), to activate immune function of Crustacea, Pisces, Aves, Mammals, and humans.