Abstract: The role of chemical phase analysis in balancing calculation for the weighted sum of tested data in complete analysis of material compositions was discussed in this paper. Based on the recommended calculation procedures and results in balancing calculation of the tested data for some representative materials with different compositions and associated minerals, a practical application of the chemical phase analysis in the tested data processing for complete analysis of the material compositions was introduced. The objects, rules and models of the application, as well as the problems which should be noted in the application process were also demonstrated.