Paper sheets were prepared by using different types of cellulosic fibers produced from agricultural wastes. Chitosan solutions with different concentrations were added to surface of paper sheets. Mechanical properties enhanced in case of treated paper sheets with chitosan comparing with untreated. Generally in all cases of paper sheets obtained from different pulps, the strength properties reached their optimum enhancement in presence of 0.5% chitosan solution almost. Optical properties enhanced by addition of chitosan. Paper sheets obtained from unbleached bagasse treated with chitosan gave the best results compared with that obtained from the others. Also paper sheets obtained from unbleached rice straw and that obtained from unbleached mixed (rice straw and 25% bagasse) gave impressive results. Crystallinity index from the ratio A 1435cm-1/ A 900 cm-1 in infra-red spectra and X-ray diffractometry proved all the above where X-ray data showed that treated paper sheets was accompanied by a significant increase in the fraction of crystalline polymer compared with untreated. It was observed from the morphology of fibers that fibers of the sized paper enhanced and became tight and smooth.