To provide a method for producing a cement composition having excellent fluidity.

This method for producing a cement composition includes: a step in which blast furnace slag obtained by melting iron ore, coke and limestone is cooled by water, then crushed, to thereby obtain blast furnace slag fine powder in which the Zr content is 250-400 mg/kg and the Ba content is 700-1,100 mg/kg; and a step in which a cement composition is prepared by mixing the blast furnace slag fine powder with cement in which the f.CaO content is 0.3-0.8 mass%.