Stress-relaxation processes of tetrafluoroethylene-propylene (TFE-P) elastomer compositions (including crosslinked and carbon-black-filled samples) were studied within the temperature range from 298 to 573 K in air over times ranging from 10(1) to 3 x 10(5) s. Using the Tobolsky-Murakami method, discrete spectra of the relaxation times (tau(i)) were determined. In the high elastic state, lambda-relaxation region transitions proceed by segmental motion, with activation energies up to 55kJmol(-1). These processes are related to the rearrangement of domains formed by different microstructures of the fluoroelastomer chain, the so-called ’soft’ rubber component. The activation energy, U(p)hi, of the phi-transition corresponds to a rearrangement of the carbon black filler network, i.e. ’hard’ rubber component. Three relaxation processes were registered in crosslinked elastomers, which are associated with changes in the chemical network. They consist of several transitions : the delta(1)-process has the lowest activation energy (U-delta 1 = 64 kJ mol(-1)) and can be related to the rearrangement of the dense sections of the chemical network, whereas the mu(F)-transition can be connected with decomposition and recombination of cross-pseudo-hydrogen bonds between fluorine and hydrogen atoms. This energy is close to the viscous flow activation energy in the pseudo-plastic region in terms of the de Waele-Ostwald equation. The other delta-process can be assigned to the high-temperature destruction of C-C bonds in the chemical network. By dynamic mechanical experiments, the principal alpha-relaxation and three beta-transitions below T-g were also registered.