Electrospinning is one of the easiest and straightforward processes of fabricating nanofibers. In this study, MWCNTs in the range of 0%, 1% and 2% up to 15% were added into polymeric solution containing PAN and dimethylformamide, and morphology and dielectric properties of electrospun nanocomposite fibers at elevated temperature were studied. Dielectric properties were measured in the temperature range between 23 and 90 0C and it was found that the dielectric constant increased with increasing the carbon nanotubes content. This may be due to conductivity and polarization effects of the nanocomposite fibers.