The F-R-F-T phase transition behavior of ferroelectric PMN-PT gradient ceramics has been investigated. Ferroelectric PMN-PT ceramics with high pyroelectric coefficients in a related wide temperature region was obtained by changing composition paralleled configuration. It is found that this kind of material obtains a high pyroelectric coefficient (27 x 10(-8) C/cm(2).K) which is four times as high as normal pyroelectric materials. The microstructure and ion diffusion of the gradient material were investigated, and the effects of them on FR-FT phase transition were analyzed and discussed.