IrO2+ZrO2 binary oxide coatings deposited on Ti substrate were prepared by thermal decomposition. The influence of the annealing temperature on the structure, surface morphology, surface composition, and capacitive performance was tested by XRD, SEM, EDX, XPS, CV, etc. The nonlinear equation q*(v)=A1exp(-v/t1)+A2exp(-v/t2)+y0 was used to calculate the active sites located inside and outside of the coatings. The results show that the critical crystallization temperature of IrO2-ZrO2 is between 340~360 °C. The phase of the coating annealed at 340 °C still remains amorphous. While annealing at 360 °C, the coatings contain both crystalline and amorphous structures. They have typical crack-like morphology and Ir3+, Ir4+, as well as higher valence Ir atoms. The specific capacitance increases with the increasing of temperature up to 360 °C, and then decreases with further increasing temperature. The electrodes annealed at 360 °C have the highest specific capacitance probably due to the optimal structures of "amorphous/crystalline mixture" which favor both electron and proton conductivity. The proton transfer has a greater influence on the capacitance than electronic conductivity. The effect of the CV scanning speed on proton migration is greater than that on electronic conductivity