The Zhazixi W-Sb deposit, located in the middle part of Xuefengshan arc tectonic zone, is one of typical vein-filled hydrothermal deposits in China. Sm-Nd and Sr isotope systematics of scheelite from the Zhazhxi W-Sb deposit have been investigated in this paper. It is shown that, there exists a relatively wide variation in Sm/Nd ratios for scheelite samples collected from this deposit (0.36~0.63), and its 143Nd/144Nd values fall in the range of 0.51211~0.51288. In the diagram of 147Sm/144Nd-143Nd/144Nd, scheelite samples are scattered displayed and have no geochronological implications for W-Sb mineralization. The Nd isotope initial compositions of analyzed samples can largely be classified into two groups, -10.2~-14.7 and -3.79~+0.01, the former are probably originated from the Banxi Group and/or underlying continental basement, the latter are likely to be derived from the underlying basic/ultrabasic rocks of Lengjiaxi Group. Contrary to the Nd isotope, Sr isotope compositions of the mineralizing fluids in the Zhazixi W-Sb deposit are relatively homogenized, the 87Sr/86Sr values of scheelite vary from 0.7304 to 0.7329. This kind of high radiogenic Sr excludes the possibilities that the ore-forming fluid of the Zhazixi deposit is derived from seawater and that host strata are sole sourebed for the ore-forming materials of the studied deposit. The underlying continental basement in western Hunan are likely candidates providing the high radiogenic Sr. Comparison with the adjacent Woxi Au-Sb-W deposit reveal both deposits display distinct differences in sources of ore-forming materials, the sourcebed of the Woxi deposit should be a older, more mature and more radiogenic Sr-rich underlying basement.