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The Xincheng gold deposit,located at the Zhaoyuan-Laizhou goldfield in the northwestern Jiaodong,is one of the most typical altered-type gold deposits. Four stages of mineralization were identified,which are pyrite-quartz-sericite stage( stage I),quartz-pyrite stage( stage II),quartz-polysulfide stage( stage III) and quartz-carbonate stage( stage IV). While,the precipitation of gold mainly occurs in pyrites from the stages II and III. The wall rocks of the deposit are the Guojialing granodiorite,comprising the quartz monzonite and monzogranite,which are generated by partial melting of the metamorphosed basement rocks of Jiaodong Group.The granulite,one of metamorphic rocks hosted in the Jiaodong Group,has a narrow δ34S range of 6. 9‰ to 9. 4‰ with an average of8. 0‰,whereas the δ34S value of Guojialing granodiorite varies in a wider range( 6. 0‰ ~ 16. 0‰,average 8. 6‰),indicating sulfur mainly derived from the granulite. The felsic dikes have a δ34S range varying from 0. 8‰ to 8. 5‰( average 6. 7‰). Among them,four δ34S values range from 7. 4‰ to 8. 5‰,showing that the sulfur of felsic dikes came from the Guojialing granodiorite and the granulite. And the left δ34S value,0. 8‰,showing certain features of magmatic origin,indicates that besides the granulite and the Guojialing granodiorite origins,the magma also provided certain portion of sulfur. The δ34S value of sulfide minerals ranges from 4. 3‰to 10. 6‰ with an average of 8. 3‰,indicating the ore sulfur may come from the Guojialing granodiorite,the granulite,and the felsic dike,and eventually derive from the metamorphosed basement rocks of Jiaodong Group. Pyrites in stage I are usually small( 5 ~600μm) and cubic,which suggests a steady metallogenic environment at a relative higher temperature( 300 ~ 350℃),low degree supersaturation of ore-forming fluid,fast cooling down,low oxygen fugacity,low sulfur fugacity and insufficient material supplies. Theδ34S value of pyrites at the stage I has a spectrum of 8. 4‰ to 10. 6‰( average 9. 7‰),indicating that the sulfur came from not only the Guojialing granodiorite,but also the granulite with a higher δ34S value. Significantly,the size of pyrites in the stages II and III varies from 3μm to 2. 5mm,and the main crystal habit is pyritohedron,which represents an ore-forming environment of medium-low temperature( 200 ~ 300℃),high degree supersaturation of ore-forming fluid,slow cooling down,high oxygen fugacity,high sulfur fugacity and sufficient material supplies. The range of δ34S value of pyrites from the stage II is 7. 7‰ to 9. 7‰( average 8. 7‰),indicating apart from the Guojialing granodiorite and the granulite,the felsic dikes having a lower δ34S value also provided certain portion of sulfur origins. The δ34S value of sulfide in the stage III has a wider range( 4. 3‰ ~ 9. 4‰,average 7. 1‰),in which the temperature has a range of 180 ~ 282℃ according to sphalerite-galena sulfur isotopic thermodynamic equilibrium,and the oxygen fugacity is about 10- 37. 3~ 10- 36. 8,indicating that the sulfur came from the Guojialing granodiorite,the granulite,and the felsic dikes.The wide range of sulfide δ34S value is the outcome of sulfur isotopic thermodynamic equilibrium fractionation. The pyrites at the stage IV are smallest( 1 ~ 5μm) and integral cubic,representing a steady metallogenic environment with lower temperature( 200℃),lower degree supersaturation of ore-forming fluids,lower oxygen fugacity,lower sulfur fugacity and insufficient material supplies.