A new strategy of microstructure design for improvement of the mechanical properties of Fe3Al based aluminides was developed. This new approach emphasizes microstructure control on the basis of ordered B2 phase structure matrix instead of the conventional D03 structure. This approach is characterized by the improvement of ductility without lose of strength. The observed data from various Fe3Al based alloys illustrated that the flattened pancake-shaped grains with ordered B2 phase structure increased both yield strength and elongation of sheet specimens compared to the equiaxed grains. The three dimensional configuration of the flattened grains and their annealing temperature dependence as well as fractography were studied.