Using copolymerization functionalization, poly[3,4-dioctyloxythiophene-alt-2,5-bis(4-vinylphenyl)-1,3,4-oxadiazole] (P3,4DOOTV-OXD) combining electrochemical properties of poly(3,4-dioctyloxythiophene) (P3,4DOOT, donor) and 1,3,4-oxadiazole (OXD, acceptor) was synthesized through Heck reaction and evaluated with 1 H-NMR, FTIR, gel permeation chromatography (GPC), UV-vis spectroscopy, photoluminescence (PL), and electroluminescence (EL) spectra. This D/A alternating copolymer, with regiosymmetrical 3,4-dioctyloxythiophene, has good solubility in common organic solvents. The optical properties investigations showed that the band-gap energy of P3,4DOOTV-OXD is 10% higher than that of P3,4DOOT (2.27 eV) at 2.52 eV in solid film. However, the photoluminescence (PL) quantum yield is as high as 57.4%, > two times more than that of homopolymer P3,4DOOT in CHCl 3 solution, and displays bright green-yellow luminescence (518 nm) in solution and yellow (542 nm) in solid film. Cyclic voltammogram indicated that the copolymer has bipolar properties, and the band gap energy (E g ) calculated based on the cyclic voltammogram is consistent with that deduced from the absorption spectra at 2.40 eV. By using indium-tin oxide (ITO) as the anode, poly(ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) as the hole-injection layer, P3,4DOOTV-OXD as the emitter and aluminum (Al) as the cathode, double-layer device with the structure of [ITO/PEDOT: PSS (50 nm)/polymer/Al (130 nm)] shows typical diode characters and exhibit bright yellow electroluminescence (562-552 nm) under the forward bias.