Abstract: An antifreeze composition comprising a glycol and water, containing (A) a phosphoric acid compound, (B) a compound of at least one metal selected from the group consisting of manganese and magnesium, (C) a corrosion-proofing agent, and optionally (D) at least one compound selected from the group consisting of (a) an aromatic polybasic acid or a salt thereof, (b) an aliphatic dicarboxylic acid or a salt thereof, (c) a molybdate, (d) a tungstate, (e) a homopolymer derived from an alkylene glycol monoallyl ether or a maleic type monomer, and (f) a copolymer thereof with another monomer and having a pH value in the range of 6.5 to 9.