Electrospinning was carried out with modified method for production of PAN nanofibers. To gain suitable production conditions, parameters such as solution concentration, applied voltage, feed rate, distance of two nazzle and distance between nazzle and collected drum were choosen among the effective parameters on electrospinning process and were investigated. It causes efficien production process and suitable nano scale diameter range of fibers. After obtaining optimum conditions, PAN nanofibers were electrospun from 14 wt% PAN in DMF solution at 11 Kv onto a rotating drum with different surface speed. In this state, the effect of applied drawing, which is determined by collection speed, was investigated on the degree of alignment, internal structure and mechanical properties of collected PAN nanofibers. The obtained result, show that best alignment, molecular orientation and tensile strength is obtained at product speed of 59.56 m/min. In this study, the technique of Raman Spectroscopy was used for investigation of molecular orientation. A maximum chain orientation parameter of 0.25 was measured for nanofibers collected at 59.56 m/min. In the next step, the simultaneistly setting and drawing operation was utilized for improvement properties of collected PAN nanofibers. The result of WAXD showed decrease of crystal size with increase of setting temperature. Increase of crystallinity with setting temperature was teeny. The survey of PAN nanofibers FTIR spectra, in minimum temperature (room temperature) and maximum temperature (270 °C) showed that chemical structure did n’t change in higher temperatures. Morever, the SEM’ result exhibit an increase in the diameter of PAN nanofibers with increase in temperature. The best mechanical properties of after-treted nanofibers was obtained in 270°C. Comparing electrospun PAN nanofibers in room temperature and after-treated nanofibers in 270°C, show that stress and modulus at the collection speed of 59.56 m/min, increase from 73.72 MPa and 4.18 GPa to 112.87 MPa and 7.25 GPa respectively. This show that themal treatment has affects on improvement of mechanical properties of collected PAN nanofibers.