Numerical simulation for the calculation of the profile developments of the spin-draw process in the melt spinning of poly(ethylene terephthalate) was performed. Both spinning and drawing profiles were analyzed and included the structure development of birefringence and crystallinity in the draw line. By applying a simple model describing the continuous drawing process, we made it possible to simulate the spin-draw process. The strain rate of the spinline had a broad distribution, and that of the draw line had a narrower peak. The calculated birefringence ranged from 0.176 to 0.192 and the crystallinity ranged from 0.37 to 0.44 with draw ratio. The birefringence profile had a similar pattern as the stress profile, and the crystallinity gently increased along the draw line more than the birefringence did. (c) 2007 Wiley Periodicals, Inc.