Abstract: The Sanchaya crystalline graphite deposit in Yichang，Hubei Province is located in the northern part of the Huangling fault dome in the upper Yangtze platform. It is one of the important crystal⁃ line graphite deposits in China. In order to further explore the genesis of the deposit，through the geological characteristics of the deposit，graphite carbon isotope characteristics，ore fixed carbon content analysis and testing，it can be seen that the ore body mainly occurs in the Huanglianghe Formation strata，and the ore type is mainly graphite schist. The fixed carbon content of graphite ore is 14.75%~19.22%，large flake graphite 85%，small flake graphite 15%. The test value of graphite δ13C‰ is -10.62‰~-11.69‰. It is speculated that the source of graphite carbon in Sanchaya graphite ore mainly comes from organic carbon and a small amount of inorganic carbon.

Key words: crystalline graphite mine, geochemical characteristics, ore genesis