Abstract: Crystalline compounds in catalysts for gas phase hydrogenation of aldehydes were determined by powder X-ray diffraction analysis, and the size of the CuO crystal in the catalyst was measured by Scherrer′s method. Results of phase analysis of crystalline compounds in a typical catalyst were found as zincite (wZnO, 63.2%), tenorite (wCuO, 34.2%) and graphite (2.6%), etc. The dimension of CuO(111) crystal plane was found to be approximately 22.3 nm as calculated by the method of chemometrical peak-shape fitting. The analytical data obtained met with the requirements of research and development of catalysts for gas phase hydrogenation of aldehydes.