The scattering properties of multi-walled carbon Nanotubes(MWCNTs)were investigated by using modal technique based on Bessel and Hankel function. It was found that the results of scattering vary with radius and numbers of carbon nanotubes. Under transverse magnetic(TM)wave conditions, the different structure of MWCNTs is not sensitive to the frequency, and the scattering intensity on the TM wave of the same radius nanotubes increases with the increasing of the number of nanotubes. Under transverse electric(TE)wave conditions, the different structure of MWCNTs exhibit high selectivity for frequency range, and the scattering intensity increases with the increasing of the radius and number of nanotubes. It is very helpful to detect infrared wave using carbon nanotubes.