Since the discovery of carbon nanotubes(CNTs), the remarkable structural, electrical and mechanical properties as carbon material has attracted many researchers, and the synthesis of high quality CNTs using various methods have studied. Kusunoki et al. have reported that CNTs with high-density and well-alignment are formed vertically on a silicon carbide substrate. CNTs on SiC substrate could be used for tribomaterial as high friction or wear proof materials because each CNT covalently bonds with the SiC substrate. Thus, we have studied about interface strength of CNT film by means of the combination of AFM nanoscratch test and finite element analysis. From the result, we could assume that shear strength at the interface of CNT films was about 180 MPa. And it was no dependency on the length of CNT.