This paper deals with the closed-loop form of mid-course guidance law design for accelerating missile system, whose acceleration is approximately constant. A midcourse guidance algorithm of feedback form is proposed to satisfy the engagement geometry conditions at the burn-out time for terminal homing performance enhancement. The effect of velocity change due to missile acceleration is explicitly considered in the derivation of the guidance law. The terminal constraint update algorithm is proposed under the assumption that the target trajectory is predicted precisely. Simulation results are provided to show the performance and characteristics of the proposed algorithm.