The paper presents evaluation of the jet damping effect on spatial motion of a homing guided missile with variable mass. The mathematical model of motion including effects generated by the burning fuel are presented – changes of mass characteristics as well as the jet damping effect are taken into account. Both the influences of inertia forces/moments and changes of the position of mass center are calculated. The damping effect generating additional forces and moments acting on the missile is also determined. The obtained set of equations of motion allows one to analyze a wide spectrum of various problems, e.g. the influence of jet damping on the homing guided missile trajectory or the dynamic response of the missile to atmospheric disturbances. Exemplary results of simulations are shown.