The application of nanostructured fibers containing natural polymers has attracted considerable attention in the various applications such as antimicrobial membranes, tissue engineering and etc. The current study involves preparation and characterization of dextran nanofiber using electrospinning method. The fiber mats with uniform morphological appearance and ultra-fine of average diameter were obtained by changing parameters such as dextran solution concentration, feeding rate, and spinning distance. The Scanning Electron Microscopy (SEM) images of the fibers, showed that the solution concentration has a noticeable effect on the formation of bead less nanofibers. Increasing the solution concentration from 0.5 g.mL-1 to 0.9 g.mL-1 changed fibers structure from coarse-beaded to a uniform bead less structure. Additionally, reducing the feed rate from 1 mL.h-1 to 0.25 mL.h-1 together with increasing the spinning distance from 150 to 170 mm generally caused the diameters of the dextran fibers to decrease, with the average diameter of the obtained fibers around 227 nm.