Adaptive transmission systems could enable efficient resource utilization through the efficient allocation of time/frequency/antenna resources based on channel quality and user requirements, and channel prediction is the premise for the application of adaptive transmission techniques, especially in mobile satellite communication systems with long propagation delay. In this paper, due to the mobile terminal's movement in GEO mobile satellite communications, the evolution of the satellite channel is decomposed into the delay evolution and the amplitude evolution and discussed separately, as the delay evolution is determined by the mobile terminal's movement, and the amplitude evolution is related to the delay evolution. The correlation of the time-varying satellite channel is analyzed, based on which a feasibility study of channel prediction is conducted in GEO mobile satellite communication systems. The foundation for the application of adaptive transmission techniques in GEO mobile satellite communications is established accordingly. Nomenclature C = speed of light d f = the Doppler shift