A new fully conjugated light-emitting polymer based on phenylene-alt-thiophene backbone has been synthesized by utilizing the Stille coupling reaction. The synthesized polymer was soluble in common organic solvents such as chloroform, THF, 1,2-dichloroethane, and has good film property. The maximum photoluminescence (PL) and electroluminescence (EL) peak wavelengths of the polymer were 530 and 520 nm, respectively, in green light emission region. The turn-on voltage of polymer appeared at 9.5 V in indium tin oxide (ITO)/polymer/Al device fabrication. In this presentation, synthesis and EL properties of the polyphenylene-alt-thiophene polymer will be discussed. (C) 2000 Elsevier Science S.A. All rights reserved.