The paper continues the research of dynamics of planetary gears with elements of the increased flexibility. The ba-sis for the analytical model and input equations is the system of nine differential equations of dynamics of the plane-tary mechanism received earlier. In the generalized forces the engine moment, the moment caused by torsion of an elastic shaft of a sun gearwheel, and elastic forces in meshing of gearwheels and on satellites axes are considered. The planetary carrier’s speed is assumed to be constant. The rigidity of the axle of the satellite in the tangential di-rection considerably exceeds the rigidity of the axle in the radial direction, therefore, the displacement in the tangen-tial direction is absent. The moment of the engine changes under the harmonious law. In this case forced vibrations of a sun gearwheel and the satellite can be considered separately from forced vibrations of the satellite in the radial di-rection owing to flexibility of the satellite axle. Amplitude-frequency characteristics of these oscillations are con-structed. Characteristics of vibration processes are expressed through mass-dimensional, kinematic and strength parameters of the planetary gear taking into account flexibility of its elements. Influence of the relative height of the flexible axle section, gear ratio of the mechanism and module of gearing on the amplitude of forced vibrations and the position of the resonance area is investigated. Conclusions are drawn on limits of variation of these parameters and their influences on the structure of planetary gears.