This work investigated the effect of ethylenediamine pretreatment on reducing enzyme loading in high gravity fermentation. At optimal conditions of ethylenediamine pretreatment, 85.5% lignin was removed. Enzyme adsorption analysis using a fluorescent cellulose-binding protein showed 35.2% increase of productive adsorption of enzymes to ethylenediamine pretreated biomass, which was caused by high delignification and dramatically increased surface roughness and porosity. In SScF at 15% glucan loading, up to 82.2 g/L ethanol was achieved with a relatively low enzyme loading of 3.6 FPU/g dry matter. It suggested that the remarkably high digestibility of EDA pretreated corn stover could effectively reduce the enzyme loading in the high gravity fermentation of cellulosic ethanol.