The effects of clay on the morphology of the poly(acrylonitrile-butadiene-styrene) (ABS)/polypropylene (PP) nanocomposites were investigated. From the studies of wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) analysis of the ABS/PP (70/30) nanocomposites with clay, it was observed that most of the clay existed in the ABS matrix because of the good affinity between the ABS and clay which contained benzyl group. From the studies of the scanning electron microscopy (SEM) analysis, the size of the PP droplet decreased with clay from 16.7 to 5.6 mu m when the clay was added up to 4.0 phr. When the clay content was increased, the droplet of the dispersed phase (PP) was shown to elongated structure. The elongated structure could be explained by the decrease of the viscosity ratio of the PP and continuous phase (ABS) with clay, which corresponded to the increase of the viscosity of the continuous phase (ABS/clay). From the results of the SEM, TEM, and WAXD analysis, it is suggested that the increase of the viscosity of the continuous phase (ABS/clay) is mainly due to the location of clay in the ABS matrix.