A method for producing a cathode material for a secondary battery, characterized in that it comprises admixing a compound liberating a phosphate ion in a solution (phosphoric acid H.sub.3PO.sub.4, phosphorus pentoxide PO.sub.5, ammonium dihydrogenphosphate NH.sub.4H.sub.2PO.sub.4 and the like), water and metallic iron, adding lithium carbonate, lithium hydroxide or a hydrate thereof to the resultant mixture, and firing the resultant reaction product, to thereby synthesize LiFePO.sub.4.