The Co/Cu/Ni/Fe salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA) were prepared and characterized during this work. All the salts exhibited exothermic decomposition in DSC. The FT-IR spectra of the gaseous products evolved during TGA of NTO salts indicated the release of NO2 and cleavage of NTO ring during the course of decomposition. Thermal decomposition of TABA salts also produced NO2 on decomposition. The transition metal salts enhanced the burning rates of AP-HTPB composite propellant evaluated during this work. The best catalytic effect was obtained with Fe-NTO salt which increased the burning rate to the extent of similar to 80% as well as brought down the pressure index (n) to 0.18 (2-9 MPa). (c) 2005 Elsevier B.V. All rights reserved.