A new approach for quantitative X-ray diffraction phase analysis of a powder mixture has been developed using the doping method proposed by Popovic.Two cases of known and unknown mass absorption coefficients of amorphous materials are discussed.The weight fraction of amorphous material or unidentified phases can be obtained by this method.For the determination of multicomponent system containing n phases,in which (n-2) pure phases are deliberately added,the weight fractions of all n phases can be determined.The procedure has been tested by using four-to five-component samples,the analysis results agree well with the theory.