Polymer optical fibers, due to their flexibility, low weight, easy fabrication and low production cost, in spite of attenuation, have been considered more during recent years in comparison with glass optical fibers. In this research, production feasibility of polymeric optical nanofibers (POF) by electrospinning and its characteristics have been considered. Polymethyl methacrylate (PMMA), because its wide use in optical literature, POF, compatibility, processability and the low cost in the production of nanofibers, has been used as a core of the optical fiber. To produce oriented optical fibers with appropriate length and to coat the optical fibers, nanofiber yarn production method and dip coating method were utilized, respectively. The measurement of optical properties of samples showed that the produced nanofibers did not have optical transition properties; however, the produced film had optical transition around 90%; as a result, non-optical transition by nanofibers could be attributed to non-traarency instead of the produced film. The change in electrospinning parameters such as voltage, concentration and solvent type did not have any effect on the traarency of the produced nanofibers. Therefore, the structure of nanofibers and the film of PMMA were considered. Evaluation of differential scanning calorimeter (DSC) revealed that the glass transition temperature of nanofibers and the film of PMMA were 49.61 c and 58.86 c , respectively. Furthermore, by the observation of X-ray scattering in the wide angle (WAXS), the amorphous nature of samples and the distance between polymer chains were gained, showing a good agreement with the results obtained from DSC test. The results obtained by low angle X-ray diffraction (LAXRD) also showed the possibility of the presence of structural arrangement closed voids and three-dimensional surface fractal in the nanofibers, as well as the presence of mass fractal in the polymeric film. Assessment and computations of the results related to small angle X-ray scattering (SAXS) showed the presence of spherical and rod-shaped articles in the nanofibers and the film of PMMA with gyration radius of 16.5 and 8.51 nm, respectively. Keywords : Polymer optical fibers, Nanofiber yarn, Differential scanning calorimetery, Wide angle X-Ray scattering, Low angle X-ray diffraction, Small angle X-ray scattering.