The main aim of the study is to increase the efficiency of gasoline blending process counting the changes of feedstock, influencing on qualitative characteristics of trade gasolines. The counting became possible using computer program of gasolines octane numbers calculation "Compounding" in conjunction with the developed module of automatic chromatographic analysis data systematization. The relevance of the study is caused by the need to increase production volumes of trade gasolines that meet gasoline quality standards. Practical results: the extended formalized set of 110 hydrocarbon components, key contributors in gasoline octane number formation, was created applying the method of mathematic modeling. The new module of automatic chromatography analysis data systematization was developed in Borland "Delphi 7" workspace. In conjunction with program of gasoline octane numbers calculation "Compounding" it provides to develop blending recipes of trade gasolines marks Regular-92, Premium and Super-98, corresponding to the current Euro-2, Euro-3, Euro-4 and Euro-5 quality standards. Implementation of the module allows taking into account changes feedstock composition, varying the recipes of trade gasolines blending and formulating recommendations for involving different-composited feedstock into the blending process. Precision of the developed recipes provides the economy of expensive components, and allows getting essential economic benefit for refineries.