PZT(45/55) ferroelectric thin films were deposited on platinum-coated silicon wafers with no substrate heating using RF magnetron sputtering. The effects of target and annealing process on the compositions, structures and electrical properties of the sputtered thin films were studied. A single perovskite phase structure was obtained with post-annealing at 500°C for 60 min in O2. This crystallization temperature is the lowest value reported. Also, the PbO in the thin films is not made volatile during the annealing process, even at temperature as high as 700°C. This is in contrast to what has been reported, and the properties of the thin films are improved. The thin films have a maximum remnant polarization (Pr) of 13.8 µCcm-2 and a minimum coercive field (Ec) of 55.5kVcm-1 when annealed at 650°C for 60 min.