Based on the Gibbs free energyΔG of mineral generation at 373 K, 423 K, 473 K, 523 K temperature, the oxygen and sulfur fugacity (logfo2, logfs2) of the simple substance iron, copper and oxysulfides, total of 22 kinds of minerals and mineral combination have been calculated by the writing formulas in Excel sheet to study the geochemical character of Dayao Liuju copper deposit. Therefore, it is believed that oxygen-sulfur fugacity controlled the redox trend, and affected metal mineral assemblages precipitation and mineral assemblage zonation in Liuju copper deposit.