Chitosan is one the few nitrogen-containing natural polysaccharides. Its inherent biological and physicochemical characteristics are attributed to the unique amine functionality, and it has attracted extensive attention in research because of its potential in biomedical and technological applications. Carboxymethyl chitosan is one of the most important of Chitosan derivatives that has been synthesized by alkalization of chitosan, followed by carboxymethylation with monochloroacetic acid. In comparison to chitosan, Carboxymethyl chitosan has better biological properties and chelating abilities. Polymeric nanofibrous structures, with several useful properties, such as a high specific surface area and high porosity, are of considerable interest for various applications. Nanofibers of ionogenic polymers are of great interest because of the peculiarities of the polyelectrolytes, and also because of the possibility of nanofiber modification on a subsequent step. Although carboxymethyl chitosan is soluble in water but studies show that electrospinning of aqueous solutions of Carboxymethyl chitosan just with the addition of a non-ionogenic water-soluble polymer such as polyvinyl alcohol, polyethylene oxide is possible. The present study focuses on the effect of the solvent on the electrospinning ability of pure carboxymethyl chitosan. The solvents tested were acetic acid, formic acid and trifluoroacetic acid (TFA). The first two solvents could not produce a visible jet as the electric field was applied. Only the solution of Carboxymethyl chitosan in TFA was electrospinable and fibers were deposited on the collector. Exsistance of beads on nanofibers, suggested that optimization of the electrospinning conditions would be necessary for the preparation of a homogenous nanofiber network of carboxymethyl chitosan. One possible approach to this optimization was to mix a volatile organic solvent with TFA. Hence, TFA and dichloromethane (DCM) were mixed. With addition of dichloromethane to the carboxymethyl chitosan-TFA solution, no beads were found on the electrospun carboxymethyl chitosan nanofibers. Homogeneity of electrospun fibers also improved. Under optimized conditions (5% (w/v) concentration, TFA/DCM: 70/30) homogenous carboxymethyl chitosan fibers with a mean diameter of 261¬nm were prepared. The results show that the three parameters (viscoelastisity, surface tension and electroconductivity) have the most significant effect on the electrospin ability of carboxymethyl chitosan. To enhance the mechanical properties, natural polymers are often blended with synthetic polymers or cross linked. In this study, Carboxymethyl chitosan/polycaprolactone (PCL) nanofibers were prepared using TFA/DCM (70:30) solvent mixture. Stability of Carboxymethyl chitosan /PCL blend system was 8 times greater than pure carboxymethyl chitosan. The average diameters of the mixed fibers were in the range 277–329 nm.