Cellulose, hemicellulose, and lignin are the major chemical components in wood paper. Various types of wet and dry strength additives are used to enhance the optical and mechanical properties of recycled paper. One of possible materials is carbon nanotube. In order to explore probability of use of carbon nanotubes as reinforcing materials and to understand how carbon nanotubes affect the mechanical properties of paper, a single walled carbon nanotube is inserted into a Iβ cellulose nanocrystal, its mechanical properties are studied by using energy minimization and molecular dynamics (MD) simulations. During simulations, the crystals are stretched in axial direction at a constant speed and stress and strain are computed and recorded at atomic level. Our results show that carbon nanotube can significantly enhance mechanical properties of paper.