Abstract: It was employed that changing the processing temperature, screw speed and draw rate in order to study how PP/PA6 in situ fibrillation composite was affected by the processing conditions. The morphology and mechanical properties of the composites, which were processed under different conditions, were investigated in the present study. It was found that at the higher screw speed, the higher draw rate and the lower processing temperature the PA6 fibrils were finer and the mechanical properties of PP/PA6 composites were better.