Spinel lithium manganese oxide (LiMn2O4) fine particles are prepared by on ultrasonic spray pyrolysis method from an aqueous lithium nitrate and manganese acetate solution. The effect of synthesis factors, such as initial concentration of feed solution and gas flow rate, on particles morphology, composition and crystallite size is examined. The effect of axial temperature profile in the aerosol flow reactor on the morphology of prepared particles is also investigated using a tubular furnace with six independently controlled heating zones. Spinel LiMn2O4 fine particles are successfully prepared at both constant temperature distribution (1,073 K) and increasing temperature distribution (473 K-473 K -673 K-873 K-1,073 K-1,073 K) in the reactor. The particles prepared at a constant temperature profile (1,073 K) in the reactor are hollow spheres, which are formed by over ten nanometer size of crystallite, while those prepared at increasing temperature profile (473 K-473 K-673 K-873 K-1,073 K-1,073 K) are shrinking and not hollow spheres.