Up to now, much research carried out about nanofibres properties and their applications. Because nanofibers have unique properties they are known as advanced materials. Therefore, there have bee many different way for producing nanofibers, such a drawing, phase separation, self-assembly, template synthesis, centrifugal and electrospinning. In the past decade, electrospinning as an effective method for producing nanofibers, has attracted attention of many researchers and industrialists. From the beginning of this century, researchers have done many studies about electrospinning process. Furthermore, electrospinning is a more inexpensive method than others. However, one of the existent drawbacks of this method i low production rate. The applications of nanofibers, are in different area such as filtration, tissue engineering, drug delivery and carbon nanofibers. Hence researchers have tried to design electrospinning systems with high production rate. The needless electrospinning technology was first patented at the Technical University of Liberec in 2003. In 2004, with the help of Elmarco Company, this idea was attempted to be commercialized for the mass production of nanofibers. Although, appearance of the needleless electrospinning systems as suitable methods for producing nanofibers in recent years was a revolution but the lack of comprehensive information is a challenge about physical and mechanical properties of nanofibers produced with this systems. The main purpose of this study is evaluate the physical and mechanical properties and morphology of fibers produced by the needleless electrospinning system. Eventually the results of this study were compared with the results of nanofibers produced in the conventional electrospinning system. For this reason, experiments were designed with the Taguchi method to investigate the cases mentioned above. In these experiments a group of parameters as variable parameters and others were considered as a response parameters, and the influence of variable parameters on the conditions of production and the response parameters were studied and analyzed. Variable parameters were concentration, distance to the collector and needles rotary speed. Change on the variable parameters were investigated, and their impact on the response parameters such as stress, elongation, modulus and fibers diameter. The results showed that the concentration has the greatest impact on the stress and elongation and distance to the collector is most effective parameter for the elastic modulus. Also, the stress for fibers produced by needleless electrospinning system was lower compared to conventional electrospinning system. In addition, the investigation showed needleless electrospinning system used in this study has the ability to produce very fine fibers. After these experiments, in order to improve the mechanical properties of electrospun fibers, single wall carbon nanotubes were used. The results showed that the stress of the fibers produced with carbon nanotubes has improved in compare to the fibers produced with pure polymer. Also the elongation of samples with carbon nanotubes were increased in compare to the samples without carbon nanotubes, and in some cases it shows higher elongation than the fibers produced by conventional electrospinning system. In general, the modulus of samples with carbon nanotubes was very close to the modulus of fibers produced by conventional electrospinning system, and in some cases, their modulus were increased significantly. Fibers diameter is important parameter among the others. The results showed that high concentrations of polymer and carbon nanotubes produced larger diameter fiber. Key Words: Needleless electrospinning, Taguchi method, Physical and mechanical properties, Carbon nanotube, Fibers diameter