Comparison geochemical characteristics of granite from northern Chifeng, Inner Mongolia with various type of granite at home and abroad and the discrimination show that most of the Chifeng granite belongs to I-type granite, and a small number of A-type with. Integrating the outcome of this paper and previous studies, the authors infer that the granite formed under the stretching and thinning environment. In this process, reducing the pressure and the upwelling of asthenosphere partial melting of the crust plays a role, so as to provide the conditions for the formation of granite.