|Abstract:The Longshan Au-Sb deposit is a typical Au-Sb ore deposit in central Hunan. Analysis and comparison on S, Pb and Sr isotopic composition of different ores, wall rocks and regional strata from the Longshan deposit have been carried out in this study. The δ34S values of ores vary from -3.0 ‰ to 5.1 ‰ with an average of 2.3‰ and the δ34S values of wall rocks vary from 4.0‰ to 5.9‰ with an average of 5.2 ‰, and the δ34S value of the regional strata from 9.3 ‰ to 13.3‰ with the average of 11.3‰. The sulfur isotopic compositions of ores differ from the data of the wall rocks and the regional strata, and it shows the magmatic character. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of ores are 16.992~18.457, 15.392~15.722 and 37.586~38.960, respectively; the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of wall rocks are 17.630~17.993, 15.522~15.644, 38.981~38.366, respectively; and the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of regional strata are 17.566~18.092, 15.430~15.630 and 37.988~38.710, respectively. The Pb isotopic compositions of ores vary to a great extent, and the sources are complicated, where the strata, Indosinian magma and upper mantle are all possible lead providers. The (87Sr/86Sr)i range of fluid inclusions in quartz is 0.71540～0.72309, the (87Sr/86Sr)i range of wall rocks is 0.71844～0.72153; the (87Sr/86Sr)i range of regional strata is 0.71792～0.71939. The initial Sr values of ore rocks, wall rocks and regional strata are all comparatively high, suggesting that they might mainly have come from the crust, with some Sr from ore-bearing strata and some from Indosinian magma. The ore-forming materials in Longshan deposits show characteristics of crust-mantle mixture, in which the ore-forming sulfur originated from magma while the other ore-forming material are partially from the regional strata of Jiangkou Formation, and partially from the Indosinian magma.