The electrical properties in graphite nanosheet (GN) filled polymer blends which are immiscible with each other were studied as a function of the polymer's blend ratio. The electrical conductivity of polymer blends is found to be determined by two factors: the double percolation effect and the crystalline change of the polymer blends. The SEM micrographs show that GN preferientially distributed unevenly in high-density polyethylene (HDPE). The selective localization of GN in polyblend is also closely related to the crystalline change of polymer blend. The degree of crystallinity of composite is different at different polymer's blend ratio and thereby influences the localization of GN in the polyblend. The piezoresistive behavior of immiscible conductive blends was investigated to gain better understanding of relationship between morphology and electrical conductivity. (c) 2007 Published by Elsevier B.V.