PVDF membranes of high beta-phase content could be obtained using the electrospinning process, with the addition of small amounts of MWCNTs (0.2 wt%). The electrospinning process is similar in some ways to uniaxial mechanical stretching, which helps the alpha-phase conversion into the betalpha-phase. Addition of long MWCNTs promoted the conversion of the PVDF molecules’ alpha-phase into thebetaa-phase by acting as nuclei in the crystallization process and inducing charge accumulation at the interface. The change of the physical properties could be attributed to the alterations in the polymer microstructure produced by drawing and poling, and to the presence of the carbon nanotubes. The cooperative effect of the drawing process and MWCNTs led to a high degree of conversion from the nonpolar alpha-phase to polar betalpha-phase in the electrospun PVDF/MWCNTs composite nanofibers. The significant effects of the polymer chain orientation originated mainly from their determining role in confining the dipole through chain rotation under drawing and poling. Differently from the solution casting membranes, depoling was not observed with excessive MWCNT addition that led to the beta-phase content decrease. For electrospun samples, it seems that depoling did not happen because of better dispersion of MWCNTs so that the charge accumulation at the interface did not exceed the coercive field. For the poled samples, the amount of the beta¬-phases increased with increasing amounts of MWCNTs, due to the efficient charge accumulation. The high conversion of alpha-phase into beta-phase was improved remarkably by further drawing of the membranes which resulted in the rapid enhancement of the ferroelectric and piezoelectric properties of the PVDF/MWCNT membranes.