Conjugated polymers have amazing potential as the components of polymeric light emitting diodes (PLEDs), organic field transistors (OFETs) and organic photovoltaic cells (OPVs). In these conjugated polymers, cyclopentadithiophene based polymers show excellent device performances. In this research, the cyclopentadithiophene analogues have been synthesized and characterized by 1H-NMR and mass spectroscopies. Obtained cyclopentadithiophenes and oligomeric molecules were polymerized by oxidative polymerization or direct arylation. The optical and electrochemical properties of the copolymers were measured by cyclic voltammetry and UV-vis spectroscopy. Hole transporting characteristics particularly mobility of these polymers were observed by OFET devices fabricated from chlorobenzene solutions of these polymers varying annealing temperature.