Dialkoxysubstitued thiophene monomers were synthesized by the nucleophilic substitution and transetherification reactions. Electrochemical homopolymerization of 3,4-dioctyloxythiophene (DOOT), copolymerization of 3,4-dimethoxythiophene (DMOT) with DOOT were carried out via potentiodynamic and galvanostat methods in the supporting electrolyte. The polymers were characterized via cyclic voltammetry (CV), scanning electron microscopy (SEM), gel permeation chromatography (GPC). In the polymerization process, the electroactive copolymer was formed on the electrode surface with the Eonset(ox) at 970mV, which is 20mV higher than that of DOOT. The Eredox of the copolymer was approximately 15mV higher than that of POOT. The momorphology studies indicated that the electrochemical deposition of P(DMOT-co-DOOT) proceeds via a mechanism of nucleation and two-dimensional (2-D) growth.