A facile and effective transformation of alpha to beta phase in electrospinning of PVDF was demonstrated by adding emeraldine base polyaniline ( PANI). Results from FTIR and X-ray studies revealed that a very large amount of the electraoctive beta-phase can be obtained by controlling the amount of PANI loading and the electrospinning parameters, whereas the gamma-phase normally showed a very tiny amount, much lower than the beta-phase, for all samples with PANI loading. The above results indicate that the addition of PANI into the PVDF solution during electrospinning is a powerful way to enhance the electroactive beta-phase of the fibers, which is significant for developing high-performance fiber-based piezoelectric devices.