The Pb-based complex perovskite relaxor ferroelectrics (RFE) of PMN and PZN ceramics were prepared. The microdomain-macrodomain transition of relaxor ferroelectrics was investigated by conventional method deeply by using amending local freezing glass-model. The structural fluctuation has taken place in RFE during the microdomain-macrodomain transition. The larger the structural fluctuation of RFE was, the lower the relaxation degree was in the same frequency condition. The relaxation degree was dimi- nished or even vanished when the microdomain became larger.

Key words: ferroelectrics, relaxor, structure, domain