Modeling studies on high speed spinning process were carried out for nylon 6 Rber. It is assumed that the bireftingence ($Delta$n) depends on the temperature(T) and the stress(o). and the rate of crystallization on $Delta$n and T, Computer calculations were carried out for steady state governing equations of melt spinning in combination with assumed relationship. Calculated results were in good agreement with those of other researchers. The velocity gradient increased with increasing spinning speeds and decreasing out-put rates. The bireftingence was increased with spinning speed. and then approached to the assumed maximum value when the speed was around 7000m1min. It is suggested that the proposed birefringence correlation is applicable to calculate the development of bireflingence in the high speed spinning of nylon 6.