A heteroepitaxial (001)Pb(ZrxTi1−x)O3(PZT) film was grown on the (100)Ir/(100)YSZ/Si structure with a cube-on-cube relationship by using reactive sputtering. The X-ray diffraction patterns of this sample showed that the double domain crystal layer of the (110) IrO2 was formed between the Ir and PZT films. According to reflection high energy electron diffraction observation and X-ray photoelectron spectroscopy measurements, it was found that the initial epitaxial growth of the PZT film occurred on the Ir film. The polarization-electric field hysteresis loop of the 285-nm-thick epitaxial PZT film with the top electrode of IrO2 showed a saturated square shape at the ac amplitude of 3V, and the remanent polarization 2Pr and the coercive field 2Ec were 80 µC/cm 2 and 100 kV/cm, respectively. The 2Pr's were not reduced up to the switching cycles of 5 × 1010 with ± 5V bipolar pulse.