An aluminized AP/HTPB propellant formulation was experimentally studied, and the effect of formulation parameters i.e. particle size of AP, catalysts on burning rate and pressure exponent were discussed. The results show that the burning rate of propellant decreases with increasing the average AP particle diameter but with large diameters the dependence of burning rate becomes weak. Liquid ferrocene catalyst is more effective to increase the burning rate as compared to solid iron oxide. A 50% rise in burning rate with liquid ferrocene catalyst is observed while 22% rise with solid catalyst.The experimental results of burning rate and pressure exponents were compared with the calculated results of the combustion model. Model predictions and the experimental data are in good agreement.