Abstract: Aiming to improve the accuracy of XRFS analysis of iron ores,especially in the determination of total iron and sulfur,a thorough study was made and some modifications were suggested,pertaining especially to the use of a cobalt-containing flux mixture of Li2B4O7 and Li2CO3 to fuse the sample at a specified range of temperature and time for the fusion,to the use of the spectral line of cobalt as internal standard,and to the use of two separate calibration curves for total iron contents at higher and lower content ranges.Besides,in the analysis of iron ore samples containing both vanadium and titanium,the co-interference happened between these two elements was eliminated by a correction method.Analytical results obtained by the modified method met very well with the accuracy and precision prescribed.