Advanced fabrication techniques to miniaturize electromechanical systems have brought us into the regime of nanoelectromechanical systems (NEMS). Understanding the mechanical properties of NEMS components is of fundamental importance in the operation of these devices. In this paper, we have reported the deformation behavior of a single-crystal simply supported nano-beam under the uniformly distributed load. By using the molecular dynamics simulation, we have investigated the influence of span the nano-beam on the bending characters. Due to surface effect, the nano-beam shows a different behavior under the uniformly distributed load.