Preparation and morphology of Polyamide 6 (PA6)/high density polyethylene (HDPE)/Styrene/Ethylene-Butylene/Styrene grafted with maleic anhydride (SEBS-g-MA)/Modified clay nanocomposites were studied. Mixing was performed using melting process in an extruder co-rotating twin screw. After etching the materials with boiling toluene and THF at room temperature, the morphology of sample checked by scanning electron microscopy (SEM) analyses. X-ray diffraction (XRD) used for evaluation of the effects of organo-clay addition in the structure of nanocomposites. XRD traces showed that the characteristic (001) peak of the nanocomposites shifted to the lower degree region. XRD and SEM results showed more uniformly distribution and dispersion of HDPE in the PA6 matrix. Better sample morphology obtained, regarding less distance, and more uniformity between nanoparticles. The mechanical properties like tensile strength, impact strength, hardness and thermal properties of these toughened nanocomposites are discussed in terms of the nanoclay, SEBS-g-MA contents and morphology. Adding nanoclay improved hardness of nanocomposites product but reduced toughness and thermal properties. Meanwhile the presence of SEBS-g-MA as a compatibilizer improved toughness, thermal properties, hardness property, and the balance properties are achieved. POLYM. ENG. SCI., 55:29-33, 2015. (c) 2014 Society of Plastics Engineers