Nanostructures such as nanorings and nanocoils are proposed, being assembled by carbon nanotubes. The molecular dynamics simulations with the Tersoff type empirical potential are performed to estimate the buckling stresses of the nanorings and the spring constants of the nanocoils. The buckling stresses obtained from the uniform bending moment of the nanorings are lower than those by using the cantilever type model. The Stone-Wales transformation from four hexagon to two pair of pentagons and heptagons only happens when the appropriate heat treatment is given after relaxation. The spring constant of the nanocoil is estimated from the energy change according to the uniaxial deformation.