Two soluble fluorescent polymers, poly(2-decyloxy-5-(4'-tert-butylphenyl)-1,4-phenylenevinylene) (DtBP-PPV) and poly(2-decyloxy-1,4-phenylenevinylene) (DO-PPV), were prepared by a method similar to the Gilch procedure. The DtBP-PPV and DO-PPV have a same chemical structure except for the conjugated tert-bytulphenyl substituents; in the former. The polymers are characterized by using H-1 NMR, FTIR, UV-vis, photoluminescence (PL), and electroluminescence (EL) spectroscopies and thermogravimetric analysis (TGA). The H-1 NMR spectra show no tolane-bis-benzyl (TBB) structure defects in DtBP-PPV but some in DO-PPV. Both UV-vis absorption and PL emission peaks of the DtBP-PPV exhibit a red-shift phenomenon as compared with those of the DO-PPV. Moreover, with the DtBP-PPV and DO-PPV acting as light-emitting polymers separately, EL devices were fabricated with a sequential lamination of ITO/PEDOT/DtBP-PPV (or DO-PPV)/ Ca/Ag. The DtBP-PPV-based device shows a lower turnon voltage, a longer EL emission wavelength, and a higher brightness than the DO-PPV-based device. The maximum brightness of DtBP-PPV-based device is 57 cd/ m(2) at an applied voltage of 12 V.