Quasi-one-dimensional (Q1D) polymer semiconductors, poly(3-alkylthiophenes) (P3AT) attract high interest due to their perspective use as active component of molecular electronic devices, fullerene-based solar cells with reversible charge separation among them. A charge in P3AT is transferred by polaron along (1D) and between (3D) polymer chains, therefore the photoinduced charge transfer in P3AT/fullerene system should depend on the anisotropic polaron diffusion and on the charge transfer from polymer chain to fullerene molecule. Polaron possesses a spin S = 1/2, so EPR spectroscopy is one of the powerful methods for the study of such Q1D systems. This allows, especially at D-band (140 GHz) EPR, to determine separately all magnetic, relaxation, and dynamics parameters of polarons in organic Q1D solids. First results of X-band (10 GHz) and D-band EPR study of spin/charge dynamics in an initial poly(3- dodecylthiophene) (P3DDT) and in that modified by fullerene, P3DDT/C₆₀ composite, are presented. Temperature dependence of the rates of the polaron 1D and 3D diffusion in P3DDT evidences that the charge in this system moves between its polymer chains in frames of activation mechanism with E_a = 0.18 eV, whereas intrachain charge diffusion depends on interaction of a polaron with lattice phonons with hw_ph = 0.13 eV. This evidences for correlation of charge and molecular dynamics in the P3DDT sample. The non-illuminated P3DDT/C60 system demonstrate single low-field signal attributed to polarons P⁺ with g = 2.0032 in P3DDT. The illumination of the system by laser with ? = 488 nm leads to the appearance of an additional signal of polarons and also of high-field line with g = 1.9998 attributed to the fullerene anion-radical C₆₀. The intensity A of the two-component signal of the radical pair P⁺C₆₀^- depends on both the laser light intensity I_hn as A ~ I_hn ^0.16 and microwave power. An electron relaxation of the P⁺ centers was shown to be much longer then that of the C₆₀ centers. Except the intra- and interchain polaron diffusion, the light-induced charge transfer between polymer and fullerene molecules should also be in the system P3DDT/C₆₀. Besides, slow macromolecular librations and fast rotational diffusion of the fullerene molecules are realized in the system studied. As in case of other Q1D polymer systems, these processes should also be correlated in the system P3DDT/C₆₀. At X-band EPR it is impossible to determine all these processes separately. High spectral resolution provided at D-band EPR allows to study all the dynamics processes in organic polymer system. The peculiarity of light-induced 1D and 3D charge and polaron dynamics in different P3AT/C₆₀ systems obtained at D-band EPR is discussed.