Creedite and gearksutite,two rare minerals of hydrous aluminium and calcium fluorides in the world, have been found in the Xikuangshan antimony deposit, Hunan province. They were form ed in late hydrothermal stage, and their mineralo- gical characteristics,such as crystal form, chemical composition, X-ray powder diffraction data, unit cell parameters,differential thermal curves and infrared absorption spectra, have been studied. Mineralogical study of creedite sho ws that its crystals are euhedral grains 1- 10μ in diameter, its chemical composition is close to the theoretical value, its calculated crystallochemical formula is Ca3 Al2..043 F8.162 (OH)1.947(S04)1.011 2.204 H2o,quite similar to its ideal one, its unit cell parameters are ao=14.123A，bo=8.510A，Co=9,950A，β=94º54´,and V0=1187. 063A3 and its X-ray powder diffraction data,differential thermal curve and infrared absorption spectra are basically similar to those of other specimens fcund abroad. Mineralogical study of gearksutite shows that its crystals are euhedral platy and flaky grains 2-5μ in diameter, its chemical composition and crystallochemical formula, CaAl1.032 F4.038 (OH)1.033·1.100 H20, CaAl1.017 F3.977 (OH)1.074·1.092 H2O, are closer to theoretical value and ideal formula than those of known ones, and its X-ray powder diffraction data and differential thermal curve are also basically similar to those of specimens found in other areas. The infrared absorption spectra of gearksutite have been obtained for the first time by determining specimens from Xikuangshan.