In this paper, a three-dimensional elastic analysis is adopted for mechanical behaviour study of single wall carbon nanotube. Non-Local theory is applied to the shell model to accounting the size effect of nanotubes. The effect of non-local parameter is studied for displacement and stress field, as mechanical response of single wall carbon nanotube. The state equations obtained from constitutive relations and the state space method is applied for solving governing equations. By considering simply support boundary condition, the Fourier series expansions are used to reducing the order of coupled governing equations to ordinary differential equations. A commercial finite element code is also carried out for validation of present work. The numerical parametric study is carried out to show the effect of non-local parameter and size effect of nanotubes like thickness to radius and radius to length ratios. Results reveal that excluding small scale effect caused missing in accuracy of stress and displacement field.
