The Ashele large scale copper—zinc deposit is a typical volcanogenic massive sulfide deposit in China, which is hosted in the marine volcaniclastic—sedimentary sequence of the Early to Middle Devonian Ashele Formation. No. 1 orebody occurs as stratoid or large lenticular. The structures of ores are massive, disseminated, ribboned, banded and veinlet. In this paper, we analyzed the helium and argon isotopic compositions of fluid inclusions in pyrite from massive, disseminated, ribboned ores. The 4He content vary from 64.5×10-7cm3STP/g to 173.0×10-7cm3STP/g, the n(3He)/n(4He) ratios are 0.1358 Ra to 0.379 Ra, and the contents of He derived from mantle vary from 1.79% to 5.55%, all of these characteristics suggest that the He in ore forming fluids should mainly be derived from crust. The 40Ar content vary from 0.318×10-7 cm3STP/g to 4.69×10-7 cm3STP/g, the n(40Ar)/n(36Ar) ratios are 389.1 to 9425，and the 40Ar* content vary from 24.06% to 96.89%，indicate the existence of seawater in ore forming fluids, which contain radioactive Ar. Combining hydrogen, oxygen and sulfur isotopic characteristics of the Ashele copper—zinc deposit, it can be concluded that the ore forming fluids were a mixture between crustal derived seawater and mantle derived magmatic fluid, and the crustal derived seawater is dominated.