In this paper a new method of X-ray quantitative phase analysis is proposed for analysing samples with or without pure phase standards. It isn't necessary to add intternal standard to samples when measuring the intensities of the analyzed phases. The effects of apparatus attenuation can be excluded by using outer standard, a pure reference phase. For this method, there are two sets of parameters, Kjs and usj(j=1，…，n);n is the number of analyzed phases; s represents reference phase, which can he obtained by means of measuring m typical samples(m>=n)and computing the least square solutions of two-paired system of linear equations shown as (6)and(7). After determination of the parameters, each sample can be analyzed independently and simply. The discriminant cf residual phase defined by equation(15) plays an important rule in guiding quantitative analysis and simplifying the operation. In addition,a detailed discussion is given concerning the calculation of samples containing amorphous or unknown phases, the measurement of the absorption coefficient of a sample, and the intensity correction for superposed peaks. The author points out in this paper that this method has overcome various defects existing in other procedures and that, being convenient, practical, adaptable and stable, it has many distinctive features. It has been successfully used in the analysis of thousands of samples, such as scpiulitc clay and magnesium chloride hydroxide cement.