The influence of certain barium and cobalt salts was studied on the burning rate- pressure relationship or double-base propellants. Among barium salts, barium-β-resorcylate produced the best catalytic effect with significant plateau effect in the 35-70 kg/cm2pressure range, whereas among the cobalt salts the best results were obtained with cobalt stearatc in the low pressure range and with cobalt salicylate in the high pressure range. These salts were found to dccompose in the surface temperature range of double-base propellants. and propellants containing them decomposed at lower temperatures than the control.