The spunbond is one of the most widely used methods of producing nonwovens. It is based on the melt spinning technique and has many similarities to it. Continuous filament nonwovens are fabrics produced by the direct lay processes, wherein webs are made directly from fibers as they are being spun from molten polymers. In this study, to investigate spunbond nonwoven and filament formation behavior of spunbond process for PP & PET was conducted. Shear rate was controled by throughput rate, and spinnabilty and filament formation behavior of PP, PET were evaluated at various spinning velocities, were analyzed through DSC, birefringence, and tensile test, etc.