PVDF nanofibers were electrospun from solution in dimethylacetamide (DMAC)/ acetone mixed solvent at temperatures ranging from 25 ˚C to 55 ˚C with a goal of maximizing the [beta] crystalline phase which has piezoelectric properties. Between 12 and 18wt% of Poly (vinylidene fluoride) (PVDF) was dissolved in the solvent(14v% to 50v%) and nonsolvent mixture(50v% to 86v%). The solvent capable of dissolving PVDF pellets is DMAc and the acetone is latent solvent which requires high temperature to dissolve PVDF. Acetone which has high volatility was added to improve the electrospinning process by changing viscosity of solution and evaporation of solvent. Its effect on viscosity and evaporation influenced by the polymer concentration and the spinning temperature is responsible to produce different fiber morphology and crystalline phases. Fiber diameter ranges from 0.1 to 3.6[mu]m. Smallest fibers are found when the spinning solution combines lower PVDF concentration as 12 or 14wt% and higher volume percent of acetone, 83 or 86v%, regardless of spinning temperature. Although finest fibers with best fiber morphology are found at high volume percent of acetone, those fibers do not possess high %[beta] crystallinity as there is no correlation between fiber morphology and the crystallinity. However, those fibers which exhibit high %[beta] crystallinity also present uniform fibers without residual solvent or beads. Obtained by XRD, %total crystallinity and %[beta] crystallinity have correlation so fibers with high crystallinity could have high piezoelectric properties. Total crystallinity measured by XRD has a maximum of 52% when the fibers are spun from the solution of 12wt%PVDF and solvent of 80v%acetone and 20v%DMAc at 55˚C. The same solution produces the fibers with maximum [beta] crystallinity 35%. The maximum 35% [beta] crystallinity is also achieved under other spinning conditions. Analyzing XRD results from different composition concludes that there are many ways to increase %[beta] crystallinity. Investigating combined effect of acetone and concentration at different spinning temperature shows significantly varying results at different temperature. At different temperature, %[beta] crystallinty correspond differently to the combined effect and the simplest way is to use spinning temperature of 55˚C with 80v%acetone in the solvent. With this combination, many concentrations can maximize %[beta] crystallinity. %Total crystallinity was also investigated by DSC although there is no correlation with the data from XRD. Heat flow shows large cold crystallization peak for solution with low volume percent of acetone. This states that fibers from those solutions were not able to crystallize fully during the electrospinning process. For better understanding of spinning, rheometer was used. The study proves that the influence of the acetone on both viscosity and evaporation. The comparison with fiber morphology points the limitation of acetone to decrease viscosity on concentration and the limitation of concentration to slow evaporation rate on the volume percent of acetone. The rheology also indicates the link between spinnable condition and chain entanglement measured by storage modulus. While interaction between three variables creates complication to identify the conditions to maximize %[beta] crystallinity, also investigating many factors suggests several ways to improve formation of [beta] crystallinity. Few conditions have been located to produce fibers with high piezoelectric properties and theses conditions also produces good fiber morphology.%[beta] crystallinity of theses fibers can be increased further using other methods and the uniform fibers with the high piezoelectric properties can be applied in many ways.