Arc erosion morphologies of Ag/MeO(10) electrical contact materials after 50000 operations under direct current of 19 V and 20 A and resistive load conditions were investigated using scanning electron microscope(SEM) and a 3D optical profiler(3DOP). The results indicated that 3DOP could supply clearer and more detailed arc erosion morphology information. Arc erosion resistance of Ag/SnO_2(10) electrical contact material was the best and that of Ag/CuO(10) was the worst. Arc erosion morphology of Ag/MeO(10) electrical contact materials mainly included three different types. Arc erosion morphologies of Ag/ZnO(10) and Ag/SnO_2(10) electrical contact materials were mainly liquid splash and evaporation, and those of Ag/CuO(10) and Ag/CdO(10) were mainly material transfer from anode to cathode. Arc erosion morphology of Ag/SnO_2(6)In_2O_3(4) electrical contact materials included both liquid splash, evaporation and material transfer. In addition, the formation process and mechanism on arc erosion morphology of Ag/MeO(10) electrical contact materials were discussed.