The Xiongcun porphyry copper_gold deposit consisting of three orebodies is a newly discovered deposit in southern Tibet. The total gold resources of No. 1 and No.2 orebody amount to 246 tons, which have higher exploration extent than No. 3 orebody, with the Au concentration of No. 1 ore body being the richest. Microscope, electron microprobe analysis and simulated analysis were used to study the gold distribution and its significance. The results show that the main gold_bearing mineral is electrum. Minor or trace kustelite, sulfur_bismuth gold mineral, and gold volynskite were also been found. Gold minerals are mainly distributed inside or along the margin of chalcopyrite, and pyrrhotite, pyrite and sphalerite also contain minor gold minerals, suggesting that gold was formed at the exsolution of sulfide. Some micro_fine gold minerals are distributed within silicate minerals in the oxidized zone due to secondary enrichment process. The sizes of gold minerals are plentifully variable. The biggest gold minerals are distributed within or along the margin of chalcopyrite while the smallest ones which are mostly less than 1μm occur near silicate minerals. The modes of occurrence of gold minerals indicate that most of gold minerals are distributed along the margin of chalcopyrite. According to the experiments of Simon, gold could be infinitely miscible in metal melt at high temperature and decreased with decreasing temperature, which implies that gold could migrate outward with decreasing temperature. The existence of gold minerals in pyrrhotite, pyrite, sphalerite and gold in northwest Dongga epithermal gold deposit may be also related to the above process.