20 centuries 80 time end, in magnetism multilayer effect of gigantic magnetism resistance discovered in film (GMR) , cause academia and the high attention that produce industry, the new revolution that because it can cause magnetism,records domain and microelectronics domain. At this moment, the mine of La-Ca-Mn-O calcic titanium that is in another kind to have similar structure with Y-Ba-Cu-O of high temperature superconductor manganese base in oxide, discovered get much magnetism resistance effect greatly, call effect of gigantic magnetism resistance (CMR) . These promoted a burgeoning subject - the birth of spin electronics. Current, spin electronics has been in magnetism resistor film of resistor of random memory, magnetism numerates its advantage is shown on the of all kinds electronic parts such as diode of metal of polarization of magnetic head, spin, dynatron. A lot of institutes of our country and institution of higher learing are beginning the work of this respect synchronously with the world. The country also includes "973" key project this task.