Between rolling airframe missile and swirling propulsion jet passing through convergent-divergent nozzle of the rocket motor, occur exchanges of angular momentum which result in the increase of roll speed of the missile. This phenomena in called jet roll damping. In the study jet roll damping was formulated from conservation equation of angular momentum. And the maximum value of the jet roll damping of KPSAM was estimated with assumed swirl velocity distribution at nozzle exit and compared with result of computation of axisymmetric compressible turbulent nozzle flow.