The Chating copper-gold deposit in Xuancheng City of Anhui Province is a large porphyry deposit newly discovered in the middle and lower reaches of the Yangtze River metallogenic belt. Based on detailed ore mineragraphic research, the authors carried out the measurement of ore-forming element concentrations of main minerals from the ores by EMPA and chemical analysis, with the purpose of studying the modes of occurrence of gold and the genetic connection between gold and copper in this deposit. The hydrothermal mineralization period of the Chating copper-gold deposit was divided into 4 stages. The fire assay analysis results of single mineral show that the pyrites at the second stage (PyⅡ), the pyrites at the third stage (PyⅢ) and the chalcopyrites at these two stages are rich in gold, whereas the quartzs at all stages and anhydrites at the third stage contain almost no gold. "Visible gold" was found in the ores and they are mainly embedded as inclusion gold and interparticle gold, with a small amount of fissure gold. The major minerals of the "visible gold" are electrum, followed by native gold. "Invisible gold" is distributed unregularly in the sulfide minerals such as chalcopyrite, pyrite, sphalerite and bornite. And the "invisible gold" exhibits nanoparticle native gold in pyrite. The correlation between gold and copper and the modes of occurrence of gold show that gold and copper have a close genetic connection. Simon's experimental study reveals that the solubility of Au in Cu-Fe sulfide is very high at high temperature. The mineralization of the Chating copper-gold deposit underwent the evolution from high temperature to low temperature. As the temperature decreased, part of gold was exsolved from Cu-Fe sulfides and became enriched as "visible gold"; while the other part remained in the form of "invisible gold" preserved in chalcopyrite, pyrite, sphalerite and other copper-bearing sulfide minerals.