Abstract: The FP-virtual synthetic standard sample was applied to the preparation of universal working curves used in XRFS determination of 26 elements in a variety of Fe-based alloys.Optimum working conditions of the instrument and rational analytical spectral lines of the elements determined were chosen in the study.Correction coefficients of spectral overlapping of 9 elements with their coexisting elements were determined,and interferences caused by background and channel materials were eliminated by the Rayleigh scattering.After supposition of the contents of the alloying elements of the virtual synthetic standard sample and calculated values of their fluorescence intensity,their final fluorescence intensity were calculated by the algorithm of FP and the FP working curves were obtained finally.The working curves of virtual synthetic standard sample were used in analysis of varieties of standard samples.It was proved that the FP working curves were feasible to be used universally in the XRFS analysis of varieties of Fe-based alloys.