The process of magnetic merging which is important in magnetic field topology in cosmic plasmas is discussed. In this process the energy which is stored in the magnetic field is converted into another form of energy. The occurrence of the reconnection process in the interplanetary space is examined. The importance of the stage of time dependent processes is shown. A curvilinear coordinate system is introduced which is a simple description of the ideal MHD-equations. The nonstationary line of flux fusion is examined and conditions for fusion processes are indicated.-from STAR, 21(9), 1983