X-ray fluorescence spectrometry was applied to determine chlorine and sulfur in limestones and dolomites with pressed power pellet sample preparation. The angle scanning of SKα spectra for different CRMs was studied. It was found that the 2θ angles did not change seriously, and at the same time, the CRMs data points showed a good linear relationship between each other. These maybe indicate that the mineralogical effect can be ignored and it was feasible to prepare the samples using pressed pellets.The relative standard deviation (RSD, n=10) for chlorine and sulfur was 6.48 % and 1.03 % respectively. The proposed method was used to determine several CRMs, the results were in good agreement with the certified values.