In this study, conductive homopolymers and bipolymers of thiophene and furan were synthesized electrochemically in an anhydrous medium in a nitrogen atmosphere using LiClO4 as the supporting electrolyte and their properties (conductivities, surface structures, thermal properties) were analyzed. Homopolymers coated onto each other in different orders were also investigated. FTIR spectra were taken to analyze structural properties. Surface analyses of polymers were clarified by scanning electron microscopy (SEM). Electrochemical properties were determined using cyclic voltammetry (CV). We found that polythiophene/polyfuran (PT/PF) and PF/PT bipolymers formed a bilayer structure. To investigate the effect of the polymerization medium on the polymer structure, the conductivities of polymers were determined by the four-probe technique and magnetic properties were analyzed via Gouy scale measurements. PF and PT homopolymers and PF/PT and PT/PF bipolymers were found to have a bipolaron nature. As a result, and as shown by thermogravimetric analysis, bipolymers have higher decomposition temperatures than the homopolymers and are thermally stable. (C) 2001 Elsevier Science B.V. All rights reserved.