Thin lead zirconate-titanate (PZT) films withc-axis orientation have been grown on MgO(100) using the tripole magnetron sputtering system. This system makes it possible to sputter lead and zirconium-titanium alternately from one composite metal target. Lead concentration in the deposited films, estimated by X-ray microanalyzer, has a great influence on the crystal growth. At relatively short period of the lead sputtering cycle, the concentration increases proportionally with the transported amount to the substrate. At longer period it becomes saturated with perovskite structure due to a self-limiting process. Although a small amount of the lead deficiency affects the crystallinity and the orientation of the film, a further deficiency of lead results in the precipitation of a ZrO2phase.