Abstract: Based on some new concepts about the description of chemical kinetics of solid propellant combustion,such as dr/dt,the change of temperature with time, to represent the rate of reaction, we propose a comprehensive model describing the combustion of AP/HTPB composite solid propellant. A large number of detailedcalculations have been performed and compared with the experimental data. The calculations with relative error less than 10% make up 77%. The modeling calculations are conducted for the solid propellant containing Al ingredient and the effects of the Al additive amount and the Al particle size on the burning rate and pressure exponent are investigated. Data calculated by this method are found to be accurate to less than 10% for 90% of the results and in good agree- ment with those of the experiments. It is shown that this technique meets the requirements for quantitative estimation.