Abstract: A heterogeneous catalyst for oxidation of propylene into propylene oxide in the liquid phase which is a carrier with active components supported thereon, the latter being oxides of scandium, yttrium, indium, gallium, thallium, or rare-earth elements of the lanthanum group, or mixtures of oxides of the above metals. In addition to with said active components, the catalyst can also contain silver, oxides of vanadium, molybdenum, tungsten, bismuth, manganese, or tantalum, or mixtures of the above active components.The method for preparing the catalyst consists in that the carrier is treated with an aqueous solution of a mineral acid or a mixture of mineral acids at 80.degree. to 100.degree.C, washed with water and dried at 300.degree. to 400.degree.C. The thus treated carrier is impregnated with aqueous solutions of salts of the corresponding metals. The impregnated carrier is treated at a temperature of 700.degree. to 800.degree.C.