A development of synthetic process via rare earth complex precursors was applied to a formation of rare earth manganites which can not be easily formed by conventional (normal) process. Several compounds of rare earth manganites with various structures were successfully synthesized by this method and their crystal structures were identified by powder X-ray diffractometry. Both of the orthorhombic and rhombohedral LaMnO3 phases were prepared. LnMn(2)O(5) phase was more easily prepared by this method than by another method. The solid solution of (Sr,La)(2)MnO4 phase for various compositions were tried to prepare a single phase, especially for a composition region Sr/La ratio < 1. since this phase is normally formed for only region of Sr/La ratio greater than or equal to 1 by the solid state reaction method.