Nanorods of Ni/Fe complex metal hydroxides precursor were fabricated by a microemulsion method. The nanorods were 20~30 nm in diameter and 600~1000 nm in length, with amorphous structure. Ni/Fe composite oxides were obtained by calcinations of Ni/Fe complex metal hydroxides precursor. At 500 °C, the sample retained the morphology of the nanorods, with the same diameter to the precursor and the length shortened to 300~400 nm. The crystal phase was composed of NiO and dispersed amorphous Fe2O3. When the calcination temperature was higher than 500 °C, the morphology of the nanorods of the precursor were collapsed to nanoparticles, and the crystal phase transformed to the mixture of NiO and NiFe2O4.