This study concerns the application of enzymatic hydrolysis to modifying starchy and cellulosic materials. Corn, cassava, upright elephant ear and sugarcane bagasse were used in order to evaluate the influence of the enzymatic hydrolysis over the structural, thermal stability and crystallinity of these materials. Differential Scanning Calorimetry (DSC) was used to evaluate the thermal properties while Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Brunauer, Emmett and Teller (BET) methods were used for the structural and morphological analysis. Corn presented the highest starch yield (g of starch/g of raw material) with 40.4%. For all materials used, the crystallinity increased due to enzymatic hydrolysis suggesting that amorphous zones are attacked first. The gelatinization temperature of the starches increased as the crystallinity increased. The granules and fibers, except for upright elephant ear starch, did not change their size with enzymatic treatment and the superficial area did not increase significantly with the enzymatic treatment.