Complexes of Eu-fatty acid were synthesized with fatty acid and 1, 10-phenanthroline as ligand linked up to rare-earth ion(Eu3+) as functional light-emitting group. Then, ultrafine fibers of polyacrylonitrile (PAN) / Eu-fatty acid composite in which Eu-fatty acid acts as a model phase change luminescence material and PAN acts as a supporting material, were prepared via electro-spinning as phase change and luminescence materials. The properties of the novel phase change and luminescence fiber were characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), fluorospectrophotometer (FL), the differential scanning calorimetry(DSC). FL results suggested that under the excitation of 280 nm ultraviolet, PAN/Eu-MA composite nanofiber emitted the predominant emission peaks at 580, 593 and 614 nm, corresponding to D-5(0)-D-7(0,) D-5(0)-F-7(1), D-5(0)-F-7(2), transitions of Eu3+, respectively. The composite nanofibers have good phase change properties and excellent luminescent property. With the increasing of Eu3+ content and carbon numbers of fatty acid, the average diameters of PAN/Eu-fatty acid composite fibers increases from 285 nm to 600 nm. This technique can be used to prepare other similar phase change and luminescence bifunctional composite nanofibers.