Abstract: In this paper, the law of the coordination motion on 5-axis NC technology is studied, the coordination principle of 5-axis NC technology is proposed, i.e., general mathematical model on the conversion from the desired paths in a CAE model to motion trajectory is analytically derived. The geometrical properties of desired path, including position, tangent and curvature are related to the kinematics of coordinated motion induding displacement, feedrate, acceleration. As a result: the desired velocity and acceleration of each one motion coordinate in the coordinated motion can be worked out according to the geometrical shape of the part surfac, and the feedrate of 5-axis machine tool.