In this research, cellulose nanocrystals (CNC) were prepared with a concentration of 2% through a hydrolysis procedure using conc-entrated sulfuric acid (H2SO4). This was followed by the preparation of CNC/Klucel E nanocomposites films with various concentrations (10, 15, 20, 30, 50 %). The obtained films were investigated and evaluated using different techniques such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and tensile strength testing. Based on the results obtained, films with concentrations of 20 and 30 %, which gave the best results, were applied on aged wood specimens in order to study the influence of this nanocomposite on different properties of wood. The influence was studied in terms of mechanical properties, change in chemical composition, and change in physical appearance through tensile tests, Fourier Transform Infrared Spectroscopy (FT-IR) and color change measurements (CIE lab), respectively. The tensile strength of the films was improved after addition of CNC to Klucel E by almost 70% at 30% concentration, and compression strength for wooden samples significantly increased after using the same concentration of the nanocomposite, which reached 35 MPa.