The magnetic, relaxation and electronic dynamic parameters of polarons in an initial and in modified poly(3-octylthiophene) samples were studied by the steady-state microwave saturation method at 2-mm waveband EPR. It was shown that intrachain spin and charge transfer is mainly determined by the energy of the lattice phonons, whereas activation mechanism prevails in interchain conductivity. These processes can be backfitted by the warming and/or recrystallization of the polymer