A series of polyamide-6 (PA6)/layered silicate (clay) nanocomposites were prepared via direct melt compounding using a conventional single screw extruder, and then the effect of interfacial interaction on the characteristic internal structure and rheological properties of PA6/clay nanocomposites was investigated. XRD diffractograms indicated a large extent of exfoliation of the layered silicate entering into a strong interaction with PA6. The formation of such morphology was further supported by TEM images. In addition, various rheological properties were interpreted in conjunction with morphological characteristics depending on interfacial interaction between PA6 and the layered silicate.