Al doped ZnO is the most promising candidate for transparent electrode, because it possesses an outstanding opto-electrical property. Electrical stability of transparent electrode in harsh environment is an important factor for devices, especially for solar cell, since the increase of TCO resistance will lead to degradation of device performance. The electrical stability of AZO is not satisfactory till now because of oxidization. In this experiment, AZO film was co-doped with less reactive (silver, nickel) and high reactive (calcium) material in oxygen and electrical stability was investigated in ambient condition for 30 days. Structural, optical and electrical properties are also characterized.