A finite element simulation technique for estimating the mechanical properties of Single-Walled Carbon Nanotube (SWCNT), polymer composites is developed. In the present modeling work, individual carbon nanotube is simulated as a frame-like structure and the primary bonds between two nearest-neighboring atoms are treated as 3D beam elements. The beam element nonlinear properties are determined via the concept of energy equivalence between molecular dynamics and structural mechanics using Modified Morse potential. Young's modulus of SWCNTs is estimated to illustrate the accuracy of this simulation technique. Results show that the obtained mechanical properties of nanotubes by the present method are in good agreement with their comparable results. © 2011 Asian Network for Scientific Information.