This paper investigates the deformation mechanism of a single-walled carbon nanotube in pure bending. The molecular dynamics analysis and continuum mechanics characterisation were used together to achieve a deeper understanding. It was found that at a bending angle of 24 degrees the nanotube buckles locally, forming a kink in the middle of the nanotube. As the bending angle increases, the kink progresses along the nanotube and varies its shape in both longitudinal and circumferential directions. The kink formation can be considered as the result of rotations of planes/surfaces about the moving and stationary hinge lines. It was also found that the kink deformation influences the load bearing capacity of the nanotube. (c) 2006 Springer Science + Business Media, Inc.