Mutual entrainment phenomenon is also called synchronization phenomenon, if various synchronization patterns of mutual entrainment can be controlled freely, it is considered to be applicable to vibration control of multiple degrees of freedom system. In our previous work, we showed that the energy of a swing system can be controlled by periodic input control method, and that forced entrainment occurs in the system. In this paper, we describe the result that analyzed by simulation and experiment whether mutual entrainment occurs when two swing systems are coupled mutually and show that periodic motions of the coupled swing system are controllable by our synchronization pattern guide control method.