Institute for Safety Problems of Nuclear Power Plants, Nat. Acad. of Sci. of Ukraine and 36a, Kirova str., Chornobyl 07270, Ukraine * A new method for identifying crystalline phases in X-ray diffraction data has been proposed, which is especially useful for the study of multiphase materials (more than eightten phases) with a relatively low content (less than 1 -3 wt%). The method is based on a statistical analysis of data and provides an unambiguous non-quantitative criterion for the presence of one or another phase in the material. It has been shown that the method works reliably in cases where a significant number of reflexes (more than several dozen) on the diffraction pattern are comparable with intensity-to-noise ratio.