Hexagonal barium ferrite () nano-particles have been successfully fabricated by spraypylorysis process. precursor solutions were synthesized by self-assembly method. Diethyleneamine (DEA) surfactant was used to fabricate the micelle structure of Ba-DEA complex under various DEA concentrations. powders were synthesized with addition of Fe ions to Ba-DEA complex and then fabricated powders by spray-pyrolysis process at the temperature range of . The molar ratio of Ba/DEA and heat-treatment temperatures significantly affected the magnetic properties and morphology of powders. powders synthesized with Ba/DEA molar ratio of 1 and heat-treated at showed the coercive forces (iHc) of 4.2 kOe with average crystal size of about 100 nm.