The direction of magnetization of magnetic materials is usually switched by a reverse magnetic field produced by an external current or a permanent magnet. In current-induced magnetic switching, the reversal of magnetization and the movement of magnetic domain walls are caused by polarized current passing through the magnetic material. This is due to the exchange interaction between the 3d electron, which is responsible for the spontaneous magnetization, and conducting 4s electrons. The current-induced magnetic switching leads to nonlinear current-voltage characteristics in magnetic wires, which could be the basis for the next generation magnetic circuit.