A raw material for a silicate phosphate fertilizer comprising a slag recovered in a pre-treatment process for a blast furnace hot-metal which contains silicates as oxides of silicon in the hot-metal and phosphates as oxides of phosphorus and contains acid-soluble silicic acid in an amount of 10 mass % or more and a method for producing the raw material which comprises adding a CaO source and an oxygen source to the hot-metal in the pre-treatment process for a blast furnace hot-metal to effect the oxidation of silicon and the dephosphorization of the hot-metal, and recovering a slag containing silicates and phosphates formed by the above reactions, followed by solidification, to thereby produce a slag containing acid-soluble silicic acid in an amount of 10 mass % or more and also phosphates. The raw material has excellent properties as a fertilizer, since it exhibits excellent characteristics of dissolution of silicates and improved absorption of silicates by a plant, due to the effect of co-existing phosphate
