Polyvinylidene Fluoride (PVDF) nanofibers were electrospun by Nanospider equipment with wire electrodes. The parameters which would influence the fiber diameter were investigated in terms of solution concentration, cartridge speed (feed rate of solution), voltage, electrode distance, rotating wire speed, winding speed and slit diameter. The morphology and diameter of fibers were observed by scanning electron microscope. The results revealed that the solution concentration had significant influence on both fiber morphology and fiber diameter; the cartridge speed, voltage, electrode distance and slit diameter had slight effect on fiber diameter since the standard deviations were large; the rotating wire speed and the winding speed had insignificant influence on fiber diameter.