Plate-like Na0.5Bi0.5TiO3 (NBT) particles with perovskite structure were synthesized by topochemical microcrystal conversion from plate-like particles of layer-structured Na0.5Bi4.5Ti4O15 (NBIT) at 950 degrees C in NaCl molten salt. As the precursors of NBT, plate-like NBIT particles were first synthesized by molten salt process by the reaction of Bi4Ti3O12, Na2CO3, and TiO2. After the topochemical reactions, layer-structured NBIT particles were transformed to the perovskite NBT platelets. NBT particles with a thickness of approximately 0.5 mu m and a length of 10-15 mu m retained the morphology feature of the precursor. High-aspect-ratio NBT platelets are suitable templates to obtain textured ceramics (especially NBT-based ceramics) by (reactive) template grain growth process.