A new high-efficiency light-emitting alternating copolymer of triphenylamine and pure PPV (TPA-PPV) has been designed and synthesized. The copolymer was highly soluble in common solvents. It could be spin cast onto various substrates to give highly transparent homogeneous thin films without heat treatment. The fluorescence quantum yield in benzene is almost up to 1.00. The maximum fluorescence wavelength for this alternating copolymer appeared around 470 nm. The fluorescence of TPA-PPV solution quenched by C-60 was examined, and the result indicated that a strong interaction exists between TPA-PPV and C-60 at the exited state. A primary single-layer LED based on ITO/TPA-PPV/AI has been fabricated, and the onset voltage is only 1.5 V and a bright green light was observed. The electroluminescence spectrum gives a peak at 510 nm when the operating voltage of 17 V was applied. The photoluminescence spectrum also appeared at the same wavelength as the electroluminescence, indicating that the same excited states are involved in the two processes.