Abstract:AgSnO2 is a most potential substitute contact material for AgCdO. In practice, however, it has some congenital defects. This paper, is to focus whether wetting ability of AgSnO2 contact material can be improved and its defects can be decreased when rare earth elements are added. Young’s equation has proved that the smaller the wetting angle is, the better the material wetting ability. So, rare earth elements La and Ce were selected as additives in the present experiment. And three Ag-based contact materials were prepared with different ratios of SnO2 to La or Ce. Then, wetting angles of the contact material were measured by the sessile drop method. They were compared with the wetting angle of the AgSnO2 contact material. The measurement results show that La can improve the wetting ability of AgSnO2 contact material obviously. For further proving this conclusion, the simulation arc tests for AgSnO2 and AgSnO2La2O3 contact materials were carried on. And their microstructures were analyzed. The results prove that AgSnO2La2O3 contact material has better wetting ability than AgSnO2.