The influence of burning catalysts and main gaseous products of decomposition on the parameters for pressure differential scanning calorimetry(PDSC) characteristics equation of the burning rate have been analyzed. The results show that the pressure factormin the equation is correlated with pressure exponent and the “burning-heat factor” k_u values of RDX-CMDB propellants(R series propellants) are affected by burning catalysts,and a linear correlation or an approximate linear correlation appears in between the relative concentrations of main gaseous products of decomposition and k_u or mvalues. Therefore,It is considered that the equation can represent the correlation between PDSC characteristics and burning rate,besides,it can be also used to describe the effects of burning catalysts and to quantitatively describe the effects of gaseous products on the increase in burning rate and the decrease in pressure factor or pressure exponent. And,the active mechanism of burning catalyst could be also revealed by means of the PDSC characteristics equation.