The brand-new magnetic-fluorescent bifunctional heterogeneous nanofiber yarns have been successfully prepared by using a conjugate electrospinning method for the first time. The heterogeneous nanofiber yarns consist of [Fe3O4/polyacrylonitrile (PAN)] magnetic nanofibers and [Eu(BA)(3)phen/PAN] fluorescent nanofibers, which benefit for separating Fe3O4 nanoparticles (NPs) from Eu(BA)(3)phen complexes effectively. The morphology and properties of as-prepared samples have been studied in detail by X-ray diffractometer, scanning electron microscope, energy-dispersive spectrometer, vibrating sample magnetometer and fluorescence spectrophotometer. The results reveal that the prepared heterogeneous nanofiber yarns have large aspect ratio and uniform diameter, and the nanofibers in the yarns exhibit high orientation. The magnetism of heterogeneous nanofiber yarns can be adjusted by modulating the contents of Fe3O4 NPs. It is satisfactorily found that the fluorescence intensity of heterogeneous nanofiber yarns is much higher than that of counterpart [Fe3O4/Eu(BA)(3)phen/PAN] homogeneous nanofiber yarns under the same compositions and contents. The new heterogeneous nanofiber yarns have the potential applications in nanodevices, fluorescent labeling, etc., due to the superior magnetic-fluorescent bifunctional properties. Furthermore, the design idea and preparation technique also provide a simple but effective method for the preparation of other bifunctional or multifunctional nanofiber yarns.