Abstract: An analytical model was presented for predicting rapidly the lethality of hit-to-kill kinetic energy kill vehicle against ballistic missile carrying submunition payloads. The geometry of submunition payloads and kill vehicle were described and the lethality determination approach was proposed based on overlapping volume analysis. In addition the endgame kinematics was modeled and the killed fraction of submunition was approximated with the shot line technology. The endgame simulation shows that the influences of strike angle and impact point on the killed fraction of submunition can be obtained with the application of the lethality analytical model. It will be a useful tool for lethality assessment and interception mode adoption about hit-to-kill kinetic kill vehicle against submunition payload in midcourse phase.