Abstract: Besides the angular momentun vector and energy, there is another vector as a constant of motion in the Kepler's problem. In this paper, we deduce rotating voctor of linear central force, rotating vector of inverse cubic force, etc, and discuss their apptications.Besides the angular momentun vector and energy, there is another vector as a constant of motion in the Kepler's problem. In this paper, we deduce rotating voctor of linear central force, rotating vector of inverse cubic force, etc, and discuss their...