Abstract: To study the effects of some minerals in coarse-grained granite specimen during metasomatic process, firstly, we have observed fracture localization and propagation by using polarized light microscope that allows us to observe the association between microfracture types and mineralogical composition. The samples in this study were collected from granitic rocks in Zhejiang province, Southeast of China. Thin sections are made and examined with the aid of polarized light microscope. This research tries to make link between mineralogical composition and microstructures to determine the controls, if any, of minerals on fracture distribution; and to investigate the relationships between the microfractures and the metasomatic alteration. The results of thin section observations showed that feldspars, quartz and biotite are the main constituents of granites and we demonstrated that the mechanisms governing the metasomatic alteration of rock also lead to the development of alkali-characteristic of the granite in the study area.