A new terphenylenevinylene carbazylenevinylene alternating copolymer with the advantage of poly(pphenylenevinylene) (PPV), poly(p-phenylene)(PPP) and poly(carbazole) was designed, synthesized and characterized. The polymer structure was confirmed by various spectroscopic analyses and the number average molecular weight (M n ) of the obtained polymer was 7,800. The resulting polymer was thermally stable with high glass transition temperature (T g ) (150 o C), and was readily soluble in common organic solvents. Cyclic voltammetry study revealed that the HOMO and LUMO energy levels of the polymer were 5.37 and 2.47 eV, respectively. The ITO/ PEDOT/polymer/Al device fabricated from the polymer emitted bright sky blue light with a maximum peak of around 478 nm. The device showed the maximum brightness of 1,200 nW with a turn-on voltage of 7 V.