In order to study the effects of the initial temperature of AP/HTPB(ammonium perchlorate/hydroyl-terminated polybutadiene)composite base bleed propellant on the hitting points of the projectile scatter quantitatively, the initial temperature sensitivity factor(σ_p) of burning rate for AP particles was introduced, and calculated by three models, Glick, Kubota and BDP considering that the burning rate of AP was dominate in base bleed propellant.Based on the calculated σ_p, the internal ballistic model and 6D external ballistic model for a 155 mm base bleed projectile were built and solved simultaneously to simulate the hitting points of the projectile scatter.Results show that σ_p=0.43%/K obtained from model BDP is appropriate owing that the inner pressure of base bleed unit is close to 0.1 MPa and changes little.The sensitivity factor for the range and cornering of the projectile affected by the initial temperature of AP/HTPB propellant are 8.22 m·K^-1 and 0.477 m·K^-1, respectively, and the calculated range changing with initial temperature is very close to that from literature with the error of 12%.