Abstract: The catalysis of four TMOs (CuO,Fe₂O₃,Co₂O₃ and Cr₂O₃) and their six TMO mixtures (mass ratio:1∶1) on the combustion properties of AP/HTPB and AP/Al/HTPB composite solid propellants was investigated systematically.The results show that the action of the TMO mixtures on burning rate of the propellants can be divided into three kinds:positive,non and negative coordination effects.The TMO mixtures with positive coordination effect can extraordinarily increase the burning rates of the propellants.The action of the TMO mixtures on the burning rate of the propellant is also depedent on the kind of the propellant.