In this work, different percentages of Copper oxide have been added to double base rocket propellant (DBRP) as burning rate modifier. A conventional DBRP has been prepared and studied for comparison. The mechanical properties at different temperatures were studied. The heat of combustion and ignition temperature of the samples were measured. The performance represented by the operating pressure and the burning rate were evaluated at 8mm throat diameters. The thermal behavior of the traditional DBRP in comparison with a selected composition containing copper oxide was discussed. It was concluded that the addition of copper oxide in DBRP has positive effect on the mechanical properties of the traditional DBRP while slight increase in the performance properties was observed.