Lithium ferrites (LiFeO2, LiFe5O8) and sodium ferrite (NaFeO2) were prepared at low temperature (130-220 degrees C) by hydrothermal treatment of Fe(III) compounds (FeOOH, FeCl3 ., 6H(2)O, Fe(NO3)(3) . 9H(2)O and Fe-2(SO4)(3) . nH(2)O) with a large excess of LiOH and NaOH, respectively. One of possible polymorphic LiFeO2 with superlattice of beta-LiFeO2 are obtained by a low temperature (350 degrees C) heat treatment of the hydrothermally obtained alpha-LiFeO2 with a small quantity of beta-LiFeO2.