A set of reference intensities,ki, are required for the quantitative interpretation of X‐ray diffraction patterns of mixtures. Eachkiwas heretofore determined individually from binary mixtures of a one‐to‐one weight ratio. A procedure for the determination of allki's of interest simultaneously is presented. The X‐ray diffraction patterns of multicomponent mixtures usually contain overlapping peaks. This overlapping problem can be avoided by choosing an arbitrary reference material already present in the mixture and/or using the strongestresolvedreflections directly. These concepts are substantiated by ten examples. The maximum standard deviation of the matrix‐flushing method has been estimated to be 8%