Modeling based on equilibrium thermodynamic and physicochemical condition suggests that Bi-rich melts can efficiently scavenge Au from hydrothermal fluids, even if these fluids are highly undersaturated with respect to Au minerals. At this study the Kuh-e Dom prospecting area in northeastern of Ardestan city (northern part of Anarak metallogenic province) as the prominent sample of Iron Oxide Cu-Au (IOCG) hyrothermal deposit have been investigated by quartz-hematite-sulfide mineralization accompanied with Fe-Cu-Au assemblage. The fahlor-group sulfosalt minerals, Bi-minerals and trace metals (e.g., gold, bismuth and electrum) investigated due to achievement of chemical composition and genetic relation to Au mineralization. Au scavenging occurs efficiently by Bi-minerals such as bismuthinite (B_2.05S_2.9), emplectite (Cu_0.56Fe_0.03Bi_1.2S_2.16), and native bismuth (Cu_0.14Bi_0.86). Evidence shows release electron from reduced minerals (e.g., pyrrhotite) and consequently increase of fluid oxygen have been eventuated Bi³⁺ to Bi⁰ and precipitation of bismuth. Hence, with occurrence of magnetite as the stable buffer phase the release electron involves reduction Au⁺ to Au⁰ and adsorbed by bismuth minerals.