Two novel conjugated copolymers consisting of alternating electron-rich propylenedioxythiophene and electron-deficient 2,3-diphenyltheno[3,4-b]pyrazine or 6,7-diphenyl[1,2,5]thiadiazole units have been synthesized through palladium catalyzed Sonogashira triple-bond coupling reaction. The structures and properties of the two copolymers, P 1 , P 2 , were characterized by FT-IR, NMR, UV–Vis absorbance (Abs), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and cyclic voltammetry (CV). UV–Vis absorption spectra of the polymers show two absorption bands both in CHCl3 solution and films. The absorption peak maxima of P 1 , P 2 are 600 nm, 766 nm in solution and 627 nm, 823 nm in films, respectively. Thermal gravimetric analysis demonstrates that the two polymers are stable below 300 °C. Cyclic voltammetry studies reveal that the band gaps of P 1 , P 2 are 1.62 eV and 1.50 eV, suggesting their potential for applications as organic solar cell materials.