In this paper, we report a detailed study on the broadband dielectric spectra of a ferroelectric relaxor P(VDF-TrFE-CFE)terpolymer with different thermal historiesand electrical poling history, with the aim to explore the relaxor dynamics and their molecular origins. To gain more insight into the dynamics of the terpolymer, the polarization dynamics of the parent P(VDF-TrFE) copoly-mer was also studied under similar conditions.