PROBLEM TO BE SOLVED: To provide a raw material for phosphate fertilizers which has high fertilizer effects, although containing phosphorus in molten iron and iron oxide originated from, e.g. phosphoric acid from steel slag, and its production method.SOLUTION: A raw material for phosphate fertilizers contains CaO, SiO, POand iron oxide (based on Fe) in a total amount of 60 mass% or higher, has a basicity α, in terms of the weight concentration ratio of CaO and SiO, of 0.8-2.0 and includes 5 mass% or higher and (-6α+27α-6) mass% or lower of POand 5-25 mass%, based on Fe, of iron oxide. In the raw material for phosphate fertilizers, the total of abundance ratios of one or more of the solid solution of Ca(PO)-CaSiO, 5CaO.SiO.POand 7CaO.2SiO.POis 15 mass% or higher. Molten slag of 1,000-1,700°C having the above composition is cooled at 10°C/min or higher.
