Poly(ethylene-terphthalate) (PET) was electorspun using constant PET concentrations (15 wt %) in Trifluoroacetic acid (TFA) and Dichlormethae (DCM) solution (50:50 ratio of solvents). The applied voltage and the distance between the needle and the ground collector kept constant, while the flow rate of polymer solution was varied from 0.005 to 0.05 ml/min and two needle diameters were used. The effect of solution flow rate and needle diameters on the fiber formation was investigated for better control of the electrospinning process. The resulting nanofibers were observed using Scanning Electron Microscopy (SEM). The obtained results showed nanofibers formation with droplets and beads formation, however, at critical flow rates of PET solution uniform beadless electrospun nanofibers was organized, and uniform morphology of nanofiber was obtained