Calcites are dominant gangue minerals in the Fankou lead-zinc deposit and were formed at three stages, The studies in such aspects as chemical composition, cell paramQters, physical characters, carbon-oxygen isotopes, fluid inclusions and thermoluminescences demonstrate that the calcite formed dur- . ing the iron-lead-zinc sulfide stage is different from that formed in pre- or post-mineralization periods in that the f ormer contains more manganese and has shorter axes and slightly higher specific Uravity, hardness, and refractive indices. In addition, δ13CpDB(%0)of the former calcite varies from-5.25 to-8.15, homogeneous temperatures range from 163℃ to 219℃，and ATL/NTL ratios are distinctly greater, It is obvious from these results that the mineralization in the Fankou lead-zinc deposit is related to the hydrothermal process.