Abstract: Researches on electrically introdued fatigue of ferroelectricceramics are reviewed in the present paper. It's definition, characteristicsand behavors at different scales are introdued, including the growth offatigue cracks, initiation of microcracks, and agglomeration of pointdefects. The theory of point defect agglomeration under the cyclic electricfield is briefly described. The moving distance of a single void underdomain switchings is calculated by the theory of microsructural evolution.The evolution function of point defect concentration in ferroelectricceramics is derived under the cyclic electric field. The quantitiverelationship of point defect concentration and their agglomeration extentare given. The mechanism of electric fatigue of ferroelectric ceramics iselucidated at different scales.