The contact angles of Ag on SnO2 with different CuO content were measured by the sessile drop method, and the morphology and composition of transition zone of the interfaces were analyzed by SEM and EPMA technique. The results show that the wettability of Ag on SnO2 is improved by increasing the CuO content. The contact angle of Ag/SnO2 decreases from 90oto 29o with 7% CuO content. When CuO dopant is added into SnO2, Ag liquid can infiltrate into MeO, and a little MeO diffuses into Ag zone. So the strong interfacial bonding is obtained.