The Hutouya Pb-Zn ore deposit in Qinghai Province, a typical skarn polymetallic deposit in the Qimantag metallogenic belt, is characterized by intense magmatism and a combination of Fe, Cu, Mo, Pb, Zn and some other metallogenic elements. In this paper the authors studied in detail the typomorphic characteristics of chemical composition of sphalerite in this deposit by electron microprobe analysis so as to investigate the distribution and enrichment patterns of Fe and Cd in sphalerite from this deposit. Microscopic observations show that sphalerite can be divided into three generations varying in color from black to light yellow gradually. Accordingly, distinct mineral assemblages of ores are characterized by the variation from sphalerite-(galena-chalcopyrite)-pyrite-pyrrhotite through sphalerite-galena-chalcopyrite-pyrite-(pyrrhotite) to spalerite-galena-calcite (or quartz). Electron microprobe analyses suggest that the early-stage sphalerite exhibits enrichment of Fe and depletion of Zn, Cd. In contrast, the late-stage sphalerite shows relative depletion of Fe and enrichment of Zn, Cd. A range of ore-forming temperatures from 148 to 262℃ is estimated according to the content of FeS in the sphalerite. The deceasing content of FeS in the spahlerite in the three generations is consistent with the corresponding decrease of ore-forming temperatures, namely from 262～258℃ through 260～200℃ to 248～148℃. In combination with the sphalerite Zn/Cd ratios, it is suggested that the Hutouya Pb-Zn deposit is a mesothermal deposit. Spatially, the flowing direction of the hydrothermal flux in this deposit was consistent with the strike of the orebody from NWW to SEE. Zn increased, Fe decreased, and the range of Zn/Cd ratios increased in the flow direction. The Zn, Fe, Mn elements of sphalerite in the Hutouya Pb-Zn deposit show characteristics of the typical skarn (magmatic hydrothermal) deposit, obviously different from things of SEDEX deposits, stratabound deposits, hydrothermal and hot brine mixed zinc deposits. Coupled with the geological characteristics and ore-forming processes, the authors hold that the Hutouya Zn-Pb deposit is a mesothermal skarn-type one.