Abstract: This paper analyzes the influence on launching coordinates of ballistic missile produced by launching point position error. The change lies not only in original point but also in Eulerian angle of coordinate transformation. Therefore, based on the geometric principle of plane equation being determined and Cosine formula to calculate the angle of two planes, a simple analytical expression among launching azimuth, launching point and goal point are obtained firstly in the Earth centered Inertial coordinates. Secondly, by the aid of Earth centered Inertial coordinates , the transformation matrix between the launching coordinates with error and the true one is derived. Given the launching point and the goal, the influence on launching coordinates of ballistic missile produced by launching point orientation error can be achieved in quantified value.