Abstract: By using optical microscope, SEM, XRD and other analytical tools, the mineral component, chemical component and nephrite structure were studied and compared with nephrite produced in other areas. Analytical results indicate that the major mineralization component of Guizhou nephrite is tremolite, while the subordinate constituents are quartz and coesite composited by SiO2 and small amount of ZnO. The “water line” structure which generally observed in Qinghai nephrite was also observed in Guizhou nephrite.