In order to improve the surface properties of carbon fiber without affecting the mechanical properties of the reinforcing fibers, various monomers (pyrrole (Py), carbazole (Cz) and thiophene (Th)) were used to electrograft conjugated copolymers. The electrocoated carbon fibers were characterized with respect to their surface morphology and surface composition, using scanning electron microscopy (SEM) and FTIR-reflectance spectroscopy, respectively. In general very homogeneous and continuous coated carbon fiber surfaces were obtained. The pH-dependent zeta (zeta)-potential measurements were applied to characterize the surface properties of all electrocoated fibers. The performed zeta -potential measurements reflect that the surface state is strongly dependent not only on the composition of the grafted polymers (different homopolymers, copolymers and a single terpolymer). but also on the extent of doping by the counter ion from the supporting electrolyte.