In this paper, a novel method has been successfully developed to prepare the polyamide 6/polystyrene/montmorillonite (APA6/PS/MMT) blends. The X-ray diffraction analysis, differential scanning calorimetry, scanning electron microscopy analysis, contact angle measurement, water absorption measurement, thermogravimetric analysis and mechanical properties test were performed separately to study the effects of P(St-co-IEM)-MMT-MPS on crystallinity, morphology, water resistance, thermal stability and mechanical properties. The results indicate the addition of MMT can promote the formation of the γ-phase. Moreover, it can improve the interfacial compatibility, water resistance, thermal stability and toughness. [ABSTRACT FROM AUTHOR]