The synthesis, characterization and capacity studies of fabricated magnetic Fe₂O₃/Fe₃O₄ nanocomposites capable of adsorbing with Acid Blue 342 dye (AB) were reported. The product was characterized by FT-IR, XRD, SEM and TEM techniques. The crystallite size calculated using the Scherrer formula for the fabricated nanocomposite was about 22.38 nm. The results of SEM analysis show rough surfaces and many visible fluffy mesoporous. The adsorption properties of the Fe₂O₃/Fe₃O₄ nanocomposites for the removal of Acid Blue 342 dye (AB) were examined. By using a batch method, various parameters affecting the adsorption properties were studied. The results revealed that Fe₂O₃/Fe₃O₄ nanostructure gave high adsorption capacity equal 39.45 mg/g. The equilibrium isotherm, kinetics parameters of the adsorption process were also calculated. The study indicated that the pseudo second-order adsorption mechanism is predominate and that the overall rate of the AB dye adsorption process was controlled by the chemisorption process.