In this paper, a Sm(III) cluster-based 2D coordination polymer {[Sm(2-stp)center dot 3(H2O)]center dot(H2O)}(n), (where 2-stp = 2-sulfoterephthalate),1has been synthesized hydrothermally and doped into poly(methyl methacrylate (PMMA) fibers through electrospinning technique to get a new 1D luminescent composite fibers, Sm/PMMA. The crystal structure of Sm(III) complex has been determined by single crystal X-ray diffraction measurements. Sm/PMMA composite fibers have been characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), and thermogravimetric analysis (TGA) in comparison to that of the pure Sm(III) complex. The luminescent spectra of the composite nanofibers (Sm/PMMA) has demonstrated strong characteristic emission of Sm(III) ions and has also pointed out much better thermal stability than the pure Sm(III) complex.