Abstract: An endgame analytical model for hit-to-kill kinetic vehicle against ballistic missile under the considerations of the kinetic vehicle dimensions was presented. A method determining endgame engagement was developed by means of shot line trace technique. In addition, an aim point grid of shot lines and random hit positions generation technique was used to calculate the hit probability distribution. Example simulations show that this endgame analytical model can provide an effective calculation and analysis of endgame engagements, including the influences of the encounter parameters, kinetic kill vehicle and incoming ballistic missile dimensions, guidance accuracy and aim point positions on the hit probability.