Abstract: It is first time studied that the characteristics of silicon isotope composition combining with siliceous cathodoluminescence for country rocks and ores and thermal solution silicified quartz from Carlin-type gold deposits in southwestern Guizhou and northwestern Guangxi province in this paper．The results show that primary silicified quartz is no luminescent but quartz in country rocks and secondary silicified quartz is luminescent on the action of cathode ray; corresponding1y, it is obviously different in silicon isotope composition of country rocks and primary mineralization siliceous fluid． Based on silicon isotope dynamic fractionation principle, it is proved that geochemical action process of metasomatic alteration and mineralization while the primary ore-bearing siliceous fluid moves quickly along main passage of deep and large fracture zone from mantle to crust, meanwhile the fluid enters secondary fractures and permeates to different profitable ore-host strata．The results provide important basis for the study that mineralization materials may be directly and mainly derived from upper mantle differentiation, and bring to light plutonic exploration prospect and geochemical background forming superlarge gold deposits．