An immunostimulating agent, which can stimulate immunity effectively, is described. The immunostimulating agent contains an active ingredient including a calcium receptor activator such as γ-Glu-X-Gly [wherein X represents an amino acid or a derivative thereof other than Cys], γ-Glu-Val-Y [wherein Y represents an amino acid or a derivative thereof], γ-Glu-Ala, γ-Glu-Gly, γ-Glu-Met, γ-Glu-Thr, γ-Glu-Val, γ-Glu-Orn, Asp-Gly, Cys-Gly, Cys-Met, Glu-Cys, Gly-Cys, Leu-Asp, γ-Glu-Met(O), γ-Glu-γ-Glu-Val, γ-Glu-Val-NH2, γ-Glu-Val-ol, γ-Glu-Ser, γ-Glu-Tau, γ-Glu-Cys(S-Me)(O), γ-Glu-Leu, γ-Glu-Ile, γ-Glu-t-Leu, γ-Glu-Cys(S-Me), a cation having a valency of 2 or more, protamine, polylysine, spermine, spermidine, putrescine, cinacalcet, a cinacalcet analogue compound, and a salt of any one of the aforementioned components.