A new magnetic-fluorescent bifunctional coaxial nanobelt structure has been successfully fabricated by specially designed coaxial-spinneret electrospinning technology. As an example, terbium complexes [Tb(BA)3 (phen)] (BA=benzoic acid, phen=1,10-phenanthroline) and ferroferric oxide nanoparticles were incorporated into polymethyl methacrylate (PMMA) and electrospun into coaxial nanobelts with Fe3 O4 /PMMA as the core and [Tb(BA)3 (phen)]/PMMA as the shell. The morphology and properties of the final products have been investigated in detail by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), biological microscopy (BM), vibrating sample magnetometry (VSM), and fluorescence spectroscopy. The results show that the [Fe3 O4 /PMMA]@[[Tb(BA)3 (phen)]/PMMA] magnetic-fluorescent bifunctional coaxial nanobelts possess superior magnetic and fluorescent properties owing to their special nanostructures. The magnetic-fluorescent bifunctional coaxial nanobelts provide higher performance than Fe3 O4 /[Tb(BA)3 (phen)]/PMMA composite nanobelts. This new type of magnetic-fluorescent bifunctional coaxial nanobelt has the potential to be used in novel nano-biolabel materials, drug delivery materials, and future nanodevices owing to their excellent magnetic-fluorescent properties, flexibility, and insolubility.