The kinetics of oxidative dehydrogenation of isobutyraldehyde to methacrolein over bismuth-antimony oxide particles were investigated in both thermal balance and fixed bed reactors. For the behavior of bismuth-antimony oxide particles, the reduction rate by feed gas and the regeneration rate by air could be analyzed by applying uniform reaction model, and it was found that these reactions were first order with respect to oxygen atom in bismuth-antimony oxide. In the respect of fluids, the rate controlling step was the surface reaction which produced a mole of methacrolein dimer by the reaction between two moles of isobutyraldehyde adsorbed on two active sites and oxygen atom in bismuth-antimony oxide.