In this article, epoxy/graphite nanoplatelet (GNP) conductive composites with the low percolation threshold of similar to 0.5 vol % were prepared. The effect of microstructure, particularly the spatial distribution of fillers in the matrix on the resistivity and its dependence on temperature, also was investigated. It is suggested that the high aspect ratio and good distribution of GNPs in the matrix contribute to the low threshold of the composite. The thermal-electrical behavior of the composite is also significantly influenced by the GNP content and microstructure of the composite. When the GNP content is greater than percolation threshold, a noticeable positive temperature coefficient of resistivity disappears. It is explained by the unique conductive network formed by plane contact between GNPs, which is hardly affected by the expansion of matrix during heating. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1515-1519, 2009