In this work a simple method for preparation of acrylic nanofibres containing silver nanoparticles is investigated. Silver nanoparticles were prepared through in-situ reduction of silver ions in DMF/PAN solution and then the solution was electrospun.This was done by dissolving small amount of silver nitrate (0.05-0.5 %wt) in DMF/PAN solution and then using light and heat treatment in order to increase the rate of silver ion reduction. Light treatment process showed better results. UV–visible spectrum studies showed the existence of silver nanoparticles in the solution and the influence of reduction time and salt concentration on numbers of silver nanoparticles and their average diameters and size distribiutions were invetigated.By measuring solution conductivity, it was found that by incearsing salt concentration, solution counductivity increases.SEM images showed that increasing salt concentration leads to a decrease in nanofiber diameter and numbers of beads. By using TEM images, average size of nanoparticles and their shapes in colloidal solution and electrospun nanofibers were obtained. FTIR results showed that no chemichal reactions between polymer chains and silver ions took place. Also by increasing the amount of silver ions in PAN solution, the rate of polymerization of nitrile groups in polymer chains was increased. XRD pattern results showed that the nanoparticle of silver were produced in the solution and were present in nanofibres and these appeared to have some effects on the polymer crystalinity . . Results of reflectance spectrophotometer showed that by increasing salt concentration, yellowness index of solition was increased. The release of silver from electrospun nanofibers were determined by atomic absorbtion method.The antibacterial effects of acrylic/Ag nanofibers were examined against E.coli, S.aureus and P.aeruginos . Results showed that the nanofibers had good antibacterial performance specialy against P.aeruginosa