Carbon nanotubes are one of the candidates for the reinforcement of metals for numerous applications. In this study, the effect of CNT on the primary radiation damage of CNT-Cu nanocomposite was investigated using molecular dynamics simulations. The simulations were performed by considering primary knock-on atom with 3 and 6 keV kinetic energies in the radial velocity direction (perpendicular to the cylinder axis) at various distances from the armchair CNT with (28, 28) chirality. Equivalent simulations in the single copper crystal and crystal containing cylindrical nanovoid ("CNV") were performed for comparison. The results represent an improvement in radiation tolerance of copper composed with CNT nanofiller. In this material, CNT not only plays a sink role for point defects, but also it acts as a barrier to extend the displacement cascade. Some fluctuations in the number of the bulk vacancy around CNT-Cu interface were observed. The reason for this behavior was discussed.