PVdF-HFP nanofibers were fabricated by co-electrospinning technique. The fabricated PVdF-HFP nanofibers were characterized using scanning electron microscopy (SEM). We have evaluated systematically the effects of the most important processing parameters: voltage, solution concentration and tip to collector distance, on the morphology of the formed fibers. 7.5 wt%$sim$20 wt% PVdF-HFP nanofibers of about 495 nm$sim$2.26 $mu$m in diameter were fabricated. The average diameter of PVdF-HFP nanofibers increased with increasing concentration of PVdF-HFP solution. It is found that the concentration of PVdF-HFP polymer solution strongly affects the size of the fibers so that diameter of fibers increases with increasing concentration of the solution. Also the applied voltage is strongly correlated with the distribution of nanofibers. In addition, we found an evidence that electrostatic effects influence the stability of discharge.