The methods for determining immobile components during hydrothermal alteration of sedi-mentary rocks are proposed and the mass changes of components in altered rocks have been quan-titatively calculated according to the immobile components in the Xikuangshan antimony deposit. According to the study TiO2 and A12O3 were immobile and SiO2, K2O, Na2O, Sb, S, As, Hg, Pb and Ba were introduced components; while CaO, MgO, Fe2O3, MnO, Cu and Zn were leached ones during silicification in the Xikuangshan antimony deposit. SiO2, Sb, S and Ba were gained and CaO was lost in significant amounts. The cause that stibnite is the only ore mineral may be that ore solution lacked other metal elements.