Abstract The Dongguashan deposit in the Shizishan district, eastern China, is a large mineralized copper system within the Middle-Lower Yangtze metallogenic belt, which occurs in an intra-continental environment, and underwent a prolonged geologic history from Late Paleozoic continental rifting, through Middle Triassic continent-continent collision, to Jurassic-Cretaceous intra-continental deformation and magmatism. The main orebody occurs as a stratabound tabular system at the boundary between Upper Carboniferous carbonates and an underlying Upper Devonian sandstone sequence. It mainly consists of massive Cu sulfide lenses, stratiform Cu skarns, laminated Cu pyrite-serpentine sheet, and small anhydrite lenses. The laminated Cu pyrite-serpentine sheet is generally underlain by stratabound stringer Cu ore lenses in the Devonian footwall sandstone, whereas massive Cu sulfide lenses and overlying anhydrite layers (lenses) comprise three rhythmic sulfide-sulfate units in the main orebody. The stratiform Cu skarns commonly overlie the massive Cu sulfide lenses and are associated with sills that intruded along anhydrite layers in the host sequence, whereas small satellite magnetite orebodies commonly surround the steeply plunging quartz monzodioritic stocks (~137 Ma). There are two main styles of alteration: subconcordant quartz-sericite alteration in the sandstone footwall; and prograde and retrograde skarn alteration, with associated Cu-Fe mineralization, related to intrusion of quartz monzodioritic stocks. The first style of alteration generally envelopes the stringer Cu ore lenses, and probably reflects diffusive discharge of submarine hydrothermal fluids during the Late Carboniferous. The second alteration style is expressed as (1) magnesian skarn in the laminated Cu pyrite-serpentine sheet, and (2) calcareous skarn widely occurring as stratiform Cu skarn bodies. The prograde mineral assemblages (mainly garnet and diopside) of both skarns were commonly metasomatized by tremolite, actinolite, chlorite, epidote, calcite and quartz during retrograde skarn alteration. Eighty sulfide samples from the deposit yielded a range of34S values from 0.5 to 8.8 ‰, whereas associated anhydrites yielded34S values varying between 14.8 and 20.5‰, implying two separated sources for hydrothermal sulfur at Dongguashan. There is a striking correlation between texture and 34S values of pyrites and anhydrites. The laminated, fine-grained anhydrites have a heavier34S value (20.5 ‰) than those of coarse-grained anhydrites (14.8 ‰), suggesting a source derived from the bacteriogenic reduction of Late Carboniferous seawater sulfate. Colloform and fine-grained pyrites have a relatively low34S (1.3-5.5 ‰), whereas crystalline pyrites exhibit an increase in34S (av. 4.4→5.3→5.7 ‰) with increasing grain size. Sulfide textures, fluid inclusions, and the spatial distribution of alteration zones and Cu orebodies indicate that the Dongguashan deposit is a two-stage overprinting mineralized Cu system, in which the early-formed massive Cu sulfides and overlying sulfate caps, that was produced by Late Carboniferous sedimentary-exhalative processes, were overprinted by Late Jurassic skarn Cu mineralization.