In this study, an effective approach for enhancing the glass transition and mechanical properties of poly(methyl methacrylate)(PMMA) composite nanofibers by incorporation of MgCl2 in the electrospun solutions has been presented. Pure PMMA and various compositions of MgCl2/PMMA nanofibers were successfully fabricated by electrospinning process under optimized conditions. SEM images indicated that the nanocomposite sample containing 1 wt% MgCl7 has the lowest average diameter with narrow distribution: According to FTIR spectra of the fabricated composites, considerable increase in absorption intensity of most bands were indicated while clear shift from 1728 cm(-1) to 1735 cm(-1) related to carbonyl group has been identified. DSC thermograms demonstrated 10 degrees C to 25 degrees C enhancement in the glass transition temperature for various nanocomposite samples. The results of the mechanical properties of the composite nanofibers sample with 1 wt% MgCl2 revealed an enhancement in the tensile strength of similar to 151 % from 0.78 +/- 0.08 MPa to 1.96 +/- 0.10 MPa, and an increase in the modulus has been seen by 236 % from 27.48 +/- 4.20 MPa to 92.25 +/- 8.50 MPa, as compared to the pure PMMA nanofibers.