Up today conducting polymers are mainly studied at X-band EPR. However, the sensitivity and information capability of the method was proved to increase considerably in the study of organic polymer semiconductors at 2-mm waveband EPR. High spectral resolution at higher registration frequency/field takes a possibility to obtain all components of g- and A-tensors even for a mixture of paramagnetic centers. The method of steady- state saturation of spin packets allows one determining separately all relaxation times and diffusion constants for polaron-like charge carriers with different mobility from the analysis of their in-phase and out-of-phase dispersion components and using then an appropriate autocorrelation function. Some sulphurous conducting polymers are characterized by strongly anisotropic magnetic parameters. Analyzing the shape of out-of-phase dispersion component by means of the saturation transfer EPR (ST-EPR) method the superslow anisotropic molecular dynamics in such systems can be investigated as well. In the present report the results of the study at 2-mm waveband EPR of magnetic, relaxation and dynamics parameters of polaron charge carriers in poly(bis-alkylthioacetylene) and poly(3-octylthiophene) are presented. Two type of paramagnetic centers are stabilized in these polymer semiconductors, namely polaron moving along and between polymer chains and polaron captured on short polymer segments. The treatment of the polymers leads to a change in concentration ratio of these centers. The mechanism of charge transport in the polymers and its correlation with macromolecular dynamics in poly(bis-alkylthioacetylene) are discussed.