We investigated the electrochemical intercalation of Ca2+ or solvated Ca2+ into Marimo nano carbon (MNC) as an anode material for calcium-ion batteries. When Ca (ClO4)2 and Ca (TFSI)2 were used as electrolyte salts, the solution structure changed in the γ-butyrolactone solvent. Additionally, higher charge capacitance was obtained at the MNC electrode than at the graphite electrode. When heat-treated MNCs were used with each electrolyte (ClO4)2 intercalated better than Ca (TFSI)2.