In this paper, a new theory about the evolution of the granite magma with the same source and a new method of geological mapping of unit and super-unit system is introduced based on the evolution sequence of mineral composition and texture of granite. which can be recognized with the line of reflected spectrum of diffrent granite units. The methods of the recognizing of the unit of granites, arrangement of the unite and analyzing of the structure of the granite system are also introduced. It is proved that after the renerwing of the geological theory about granite, the advantage of remote sensing on geological mapping of unit-superunit system for granite remains with correct way and the precision of processing and the level of geological investigation can meet recent geological mapping of unit-superunit system.