Abstract: The effects of Pt/YSZ electrode activation temperature on its characteristics were studied by AC impedance, SEM observation and ultrasonic technique.The investigation indicates that as the activation temperature increases, the electrolyte resistance is constant, while the interfacial resistance of the electrodes and response time all decrease first then increase, the electrode layer adhesion increases, the length of triple phase boundary of electrode first increases then decreases.the best activation temperature is 1050 ℃ at which the electrode has the least interfacial resistance shortest response time, highest activity as well as sound electrode layer adhesion.