Hydrothermal Calcites are of main gangue minerals in the mercury metallogenic belt in Hunan and Guizhou provinces, China. REE geochemical studies on hydrothermal calcites from three main mercury ore fields (Wanshan, Chatian and Dadongla) showed similar chondrite-normalized REE distribution patterns with LREE-enriched and right-inclined type. However, in comparison with host rocks, the total REE patterns are different with each other. In the middle section of mercury metallogenic belt, similar REE distribution patterns were observed between calcites and host rock from Chatian and Dadongla ore fields, although with the slightly difference in the total REE abundances.