The transparent conductive oxide (TCO) electrode is an important part of organic light-emitting diodes (OLEDs), especially for the OLEDs based on flexible substrate. We fabricated indium tin oxide (ITO)/Ag/ITO multilayer films deposited on polyethylene terephthalate (PET) film by using sputtering technique at room temperature in order to achieve high transmittance and low sheet resistance for application to flexible OLED devices. The OLEDs made with ITO/Ag/ITO multilayer deposited on flexible film exhibited lower operating voltage and higher current efficiency than the OLEDs made with commercial single layer ITO glass substrate.