The electrosynthesis of the copolymer of bithiophene and 3-methylthiophene has been investigated using galvanostatic and potentiodynamic techniques. The most stable films were obtained using galvanostatic technique in acetonitrile solvent and TBAPF6 as supporting electrolyte. A comparison study was performed for the prepared copolymer and homopolymer films whose were subjected to a relaxation studies using cyclic voltammetric technique in different solvents. The effect of solvent, monomer concentration ratio, electrocopolymerization techniques and temperature on the relaxation time were investigated.