This work deals with the experimental study of the theological behaviour, the growth and evolution of the morphology of two components polyarylamide/polypropylene blends during injection molding. In the case of compatibilized blends, the viscosity shows two main results depending on shear rate. For low shear rates, up to 10(3) s(-1), we notice a positive deviation in comparison with the additivity low, whereas a negative deviation is observed for high shear rates including injection molding conditions. The analysis of the morphology of the blend by scanning electronic microscopy shows a dispersed phase with nodules. The injection flow rate acts on the shape of the nodules and also on their repartition as obtained from a rectangular molded plate. The thermomechanical analysis of pure composition samples (100% PA) and of a compatibilized mixture PA (70%)/PP (30%) has been studied.