Ferroelectric La doped PZT 60/40 thin films with uniform composition have been synthesized using metallo-organic precursor solutions. These metallo-organic precursors have been stored for more than four years and are very stable in ambient conditions, compared to the sol-gel solutions. The structural properties of these films have been studied using X-ray diffraction and atomic force microscopy. The excellent ferroelectric properties of the films, such as less than 10% polarization loss after 1011cycles, low leakage current of 3·06×10−12A at 2 V, and small separation of polarization peaks in a voltage loop by the small-signal measurement, are attributed to the high quality of the metalloorganic solutions used in this study, which have been carefully home-synthesized. The oxygen vacancy in the films was reduced by optimizing the annealing conditions, and to minimize the blocking oxygen vacancy at the interface by Pt electrodes a suitable amount of La ions was doped. We suggest that greater attention should be paid to the elimination/minimization of the oxygen vacancy in the ferroelectric PZT films instead of using oxide electrodes, which allow a relatively larger leakage current flowing through the films and the electrodes.