The article presents the role of sulfur-reducing additives to catalytic cracking catalysts. It has been shown that the use of desulfurizing components directly within cracking reduces sulfur content without significant capital costs compared to various methods of reducing sulfur in cracking products. Data on import additives to industrial catalysts of cracking are given. Currently, no applying domestic desulfurizing additives has been mentioned in scientific and technical literature in open press. A particular interest has been observed in mesoporous structured oxides as components of a carrier of components having an increased specific surface area, a large pore size compared with zeolites, as well as a high ability to absorb sulfur compounds achieved by varying acidity during synthesis. The catalyst activity is considered by applying the method of determination according to ASTM D3907-13. In the course of the examination, the effectiveness of using desulfurizing additives as a catalyst component for the removal of sulfur from raw materials was noted. The analysis of study methods for microspheric catalysts used in a cracking process in a reactor with a stationary layer was carried out. When the reactor was loaded with a glass wool on the bottom, three equal portions of the catalyst were laid out layer by layer with the addition of quartz grit between the layers. The free space of the reactor was filled with quartz grit and covered with a small amount of glass wool. A shortcoming of this method is in a little volume of the reaction zone, a short feed time and an ineffective way of loading the catalyst. The non-uniform distribution of the catalyst bed leads to large errors in determining its activity. When the catalyst is loaded by mixing it with quartz grit in order to determine its activity in laboratory conditions, the results obtained are similar to those used in the operation of catalysts on an industrial plant. According to the data results it was defined that the catalyst is be loaded into the reactor by mixing it with quartz granules with particle sizes of 1 mm in the ratio of a catalyst to a granule as 1:2, which corresponds to a more uniform distribution of the catalyst volume along the length of the reactor and provides less errors in determining the activity and greater volumetric feed rate.