In this paper the mechanical behavior of silicon carbide (SiC) nanotubes are investigated by molecular dynamics which an effective and accurate way of modeling the behavior of nanostructures. The interactions of atoms in SiCNT are described using the Tersoff potential. In this study both armchair and zigzag SiC nanotubes are considered. At first, the tensile behavior of single-walled SiCNTs is simulated. The generated results show that the Young’s modulus of SiCNTs is in the range of 565 ± 50 GPa. At the second stage, critical buckling load in axial compression for different length of armchair and zigzag SiCNTs are determined and the effects of nanotube length on the buckling behavior are studied. Simulations show that the critical buckling load decreases with the increase of nanotubes length. Also the results demonstrate that the critical buckling load in armchair (7,7) is lower than that of zigzag (12,0).