Abstract: The dry sliding friction and wear of W-20Cu compacts and 45 steel in the magnetic field was studied by use of a modified MPV-1500 tribo-tester at room temperature. The worn surface and sub-surface morphology of W-20Cu compacts and wear debris were characterized by means of scanning electron microscopy.The three-dimensional characteristic of the wear sample was further studied by using 3-D surface profiler and 3-D surface roughness was calculated and characterized. The results show that,by applying magnetic field and increasing the intensity,the wear rates of the W-20Cu and 45 steel and the friction coefficient were reduced. In addition, the degree of deformation of the sub- worn surface was reduced and fine wear debris was observed. The wear mechanism was mainly abrasive wear under non-magnetic field. After applying magnetic field,the wear surface of W-Cu pin became smooth gradually and the wear mechanism included abrasive wear and oxidation wear.