Various types of magnetic fields in solidification and their application are introduced, and their main pros ans cons for solidification process are discussed. There are two main kinds of magnetic fields used in solidification: steady magnetic fields and non-steady magnetic fields. The steady magnetic field includes cusp magnetic field (CMF), vertical magnetic field (VMF) and horizontal magnetic field (HMF), while the non-steady magnetic field includes rotating magnetic field (RMF), traveling magnetic field (TMF), alternating (pulsating) magnetic field (AMF, PMF) and eletromagnetic field (EMF). The prosperous future of the magnetic field process is expected.