Perovskite lead zirconate titanate (PZT) thin films were fabricated on Pt(70 nm)/Ti(100 nm) SiO2/Si substrates at 470oC and 500oC, respectively, by electron cyclotron resonance plasma-enhanced chemical vapor deposition using metal organic sources. A Pb-deficient interfacial layer was observed between the PZT film and Pt substrate by cross-sectional TEM, which seems to distort the C-V hysteresis loop of the Pt/PZT/Pt capacitor. PZT thin films deposited at 500oC had thinner interfacial layers and showed better electric properties than those deposited at 470oC. Effects of the interfacial layer and post-heat treatment on the microstructure and electric properties of PZT thin films were investigated.