Abstract: XRFS was proposed for determination of 6 elements (i.e., Mo, Fe, Pb, Cu, Si and Ca) in sample of molybdenum concentrates. The sample was fused at 1 100 ℃ using Li2B4O7 and LiNO3 as flux for 15 min, and the sample in molten state was poured into a Pt-Au mould to have it shaped upon cooling, and the melt demoulded was used for XRFS analysis. Working curve was prepared with a set of 10 calibration samples, which were prepared with high-purity oxides (i.e., MoO3, Fe2O3, SiO2) and CaCO3 as well as standard solutions (Cu and Pb). The mathematical models of matrix correction of the 6 elements were optimized. Values of detection limit of the method found were in the range of 0.003%-0.015%. Values of RSD′s (n=11) were found to be in the range of 0.066%-2.5% in the analysis of a sample of molybdenum concentrates. The proposed method was used in analyzing 2 samples of molybdenum concentrate, giving results in consistency with those obtained by chemical methods.