The effects of electron beam irradiation on the electrical characteristics of Pt-PZT-Pt and Pt-PLZT-Pt (with La concentration of 5% and 10%) thin film capacitors were studied. The top electrode of each capacitor was bombarded by localized energetic electrons with incident energies varying from 5 keV to 25 ke.V. Large distortions in the hysteresis loops were observed when the incident electrons had enough energy to penetrate the 1000Å Pt top electrode. The damage effects are strongly dependent on the original domain orientation when the film is irradiated, and an applied a.c. field after the irradiation seems to induce some recovery effects. The damage mechanism is explained by a simple model which considers the effect of space charge fields generated by the charge carriers trapped at the domain boundaries.