High strength and high conductivity Cu-Nb microcomoposites were fabricated by Accumulative Bundling and Drawing (ABD) process. The microstructure of composite and interface diffusion were observed during the four times compositing process by SEM and EDS. Crystal orientation evolution of Nb filaments and Cu matrix were characterized by XRD at extrusion and drawing conditions of different compositing process. The interface structure and crystal orientation were analyzed by HRTEM and IFFT. It is shown that the diffusion between Cu/Nb interfaces had taken place during the 3rd compositing. The texture of Nb fibers is <110> orientation while for Cu matrix is <111> orientation after the severe plastic deformation. And atomic planes (111)Cu are parallel to that of (110)Nb with a angular deviation of 18.7?, which means that a crystal mismatch dislocation appears at interval of every six Cu (111) crystal planes.