The　polarization　of　(Pb0.94La0.04)[(Zr0.7Sn0.3)(0.87)Ti-0.13]O-3　antiferroelectric　(AFE)　ceramics　under　unipolar　pulse　electric　field　was　studied,　and　the　transient　hysteresis　loop　was　achieved.　Compared　to　the　traditional　quasi-static　results,　the　forward　transition　field　increases　and　the　backward　transition　field　decreases.　The　forward　and　backward　phase　transitions　can　be　deduced　in　microseconds　scale.　Under　the　transient　field,　the　releasable　energy　density　decreases　significantly,　while　the　stored　energy　density　changes　slightly.　Consequently,　the　efficiency　decreases　and　the　declination　of　energy　density　under　transient　situation　is　verified　by　the　charge-discharge　experiment.　The　above　results　prove　the　necessity　of　the　study　of　the　transient　behaviors　in　AFE　and　the　limitation　of　quasi-static　analysis.　Published　by　AIP　Publishing.