MoO2 was produced by mixing MoS2 and MoO3 via a solid-state reaction in a fluidized bed reactor. The basic fluidization data were acquired by monitoring the minimum fluidization velocity of MoS2 and MoO3. The conversion rate of MoS2 and MoO3 to MoO2 was derived based on the solid-state reactions carried out for 1 h at various stoichiometric ratios. This study confirmed that the optimal stoichiometric ratio of MoS2 and MoO3 was 1.0 : 6. The conversion rate at the optimum stoichiometric ratio was studied by varying the reaction temperature. A conversion rate of 99% was achieved when the reaction temperature and superficial gas velocity were 973 K and 0.3m/s, respectively. Detailed analysis of the final product after the solid-state reaction was by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD), to determine the shape, structure, and diffraction patterns.