HEAT STORAGE MATERIAL COMPOSITION

A heat storage material composition comprising: (A) a linear saturated hydrocarbon compound having 2n carbon atoms;(B) a linear saturated hydrocarbon compound having (2n+m) carbon atoms; and(C) an organic compound having a molecular weight of 50 to 300, a solubility parameter of 5 to 8.5 (cal/cm3)0.5 and a melting point measured by a differential scanning calorimeter which is 30° C. or more lower than that of the linear saturated hydrocarbon compound (B), wherein “n” is a single number selected from a natural number of 4 or more, “n” in the linear saturated hydrocarbon compound (A) and “n” in the linear saturated hydrocarbon compound (B) are the same, “m” is −3, −1, +1 or +3, and the mass ratio MA:MB of the content MA of the above linear saturated hydrocarbon compound (A) to the content MB of the above linear saturated hydrocarbon compound (B) is 99:1 to 80:20