The decomposition of lignocellulosic raw material included: mechanical grinding of plant biomass, delignification (removal of lignin this process was conducted in alkaline environment) and detoxification process (removal of alcoholic fermentation inhibitory compounds). The study on producing ethanol from corn straw was based on SSF method which involved conducting simultaneous enzymatic hydrolysis of cellulose and fermentation of obtained saccharides. Based on the study of corn straw alcoholic fermentation it was determined that the way of preparing the raw material in the initial stage of simultaneous saccharification and fermentation, significantly influences the improvement of fermentation yield. In comparison with an attempt in which biomass detoxification process was not implemented, the attempt with detoxification resulted in gaining higher fermentation yield and in lowering the content of aldehydes, methanol and furfural in the produced spirit. Moreover, in the attempts in which detoxification of raw material was used, better actual speed, productivity and the yield of alcoholic fermentation of corn straw was noted. The conducted detoxification in the process of lignocellulosic biomass decomposition improved fermentation yield. (C) 2014 Elsevier Ltd. All rights reserved.