Fe(PO3)(3) with different morphologies has been synthesized using H3PO4 and Fe2O3 as starting compounds by microwave sintering. The structure and morphologies of resultant samples were characterized by X-ray diffractometry, thermogravimetry/differential scanning calorimetry, Fourier transform infrared spectroscopy, and transmission electron microscopy. The Fe(PO3)(3) crystals obtained from microwave sintering have high thermal stability and good micromorphology. The crystal transformation of Fe(PO3)(3) and the synthesis mechanism are simply discussed.