One of the biggest challenges in the production of biofuels is the development of an efficient process to increase the rate of hydrolysis of lignocellulosic biomass into its component sugars. The use of ionic liquids as ‘green’ biomass solvents for pretreatment processing has recently gained attention due to their ability to drastically reduce the crystallinity of cellulose and dissolve biomass.  Through ionic liquid pretreatment, the rate of enzymatic hydrolysis of the biomass is markedly increased compared to other pretreatment techniques. In order to understand the mechanism of ionic liquid treatment on biomass,  high resolution 2D NMR technique was employed.  Here we present the first chemical characterization of switchgrass, a leading candidate for biofuel production, using 2D NMR and examine the changes in its composition that result from ionic liquid pretreatment.