The　NiO　and　Fe2O3　powders　were　mixed　by　the　high-energy　ball-milling,　followed　by　a　sintering　of　the　mixture　at　1340　degrees　C　for　0.5　h.　XRD,　SEM,　DSC,　and　size　measurements　were　preformed　to　study　the　microstructure　evolution　in　the　high-energy　ball-milled　mixture　and　the　sintered　ones,　as　well.　It　showed　that　the　high-energy　ball-milling　processes　resulted　in　a　severe　lattice　distortion　in　the　powder　of　Fe2O3,　but　only　a　slight　lattice　distortion　in　NiO.　Meanwhile,　a　solid　solution　of　iron　atoms　into　the　NiO　lattice　was　also　detected　in　the　milling　process.　It　was　also　found　that　the　solubility　of　the　iron　atoms　into　the　NiO　lattice　delayed　the　synthesizing　reaction　in　the　following　sintering　process.