Europium complexes Eu(BA) 3 phen (BA = benzoic acid, phen = 1,10-phenanthroline) and Terbium complexes Tb(BA) 3 phen are incorporated into polyvinyl pyrrolidone (PVP) and electrospun into [Eu(BA) 3 phen + Tb (BA) 3 phen]/PVP composite nanofibers. The morphologies and properties of the final products are investigated via scanning electron microscopy, energy dispersive spectrometry,X-ray powder diffractometry, fluorescence spectroscopy, Fourier-transform infrared spectroscopy and thermogravimetry. The diameter of the composite nanofibers is 431.55 ± 3.14 nm. The obtained composite nanofibers are amorphous in structure and stable below 220°C. By adjusting the ratio of Eu(BA) 3 phen to Tb (BA) 3 phen complexes, the fluorescence color of composite nanofibers can be tuned from red to yellow, yellow green, and green under the excitation of 276-nm single-wavelength ultraviolet light. Besides, the fluorescence lifetime of Eu 3+ ions in composite nanofibers is extended gradually, while that of Tb 3+ ions is decreased slowly with increase of Tb (BA) 3 phen content. The novel color-tunable composite nanofibers have potential applications in the fields of optical devices, color displays and sensor systems.