Abstract: In the previnus paper, the field calculatin for focus deflection system of a cam-era tube with electrostatic deflection yokes were deseribed. Now that the potential field is known we can treat the trajectories described by the electrons in this field. The electron trajectory calcula-tion in the focus-deflection system with the electrostatic deflection differs from usual trial solution determined by the discrete methods in the rotationally system field. Because poteotial fuoction of the focus-deflection field determined by the analytic method are analytic fuoctions of the variations r, θ, z, in the tracing process of the electron trajectories the potential and it's deriva-tives at an arbitrary point may be given by the aoalytic fuoctions.The purpose of the paper is to give the method of solving geoeral equation of motion for an electron in mixed field which produces a combined electromagnetic focus field and the electrostatic deflection field.

Key words: camera tube, electrostatic deflection, electrostatic focus, magoetic focus