A study on the correlation between electrical percolation and viscoelastic percolation for graphite (GP) filled high-density polyethylene (HDPE) conductive composites was carried out through an examination of the filler concentration phi dependence of the volume resistivity rho and dynamic viscoelastic functions. The frequency omega dependence of G' at low omega s decreased obviously with increasing GP concentration. The relationship between phi and the proportion of dynamic storage modulus of the composites to that of the polymer matrix, namely the relative dynamic storage modulus (G'(c)/G'(p)), at low frequency region was studied. It is found that there are two critical threshold, phi(r1) and phi(r2), in plots of phi similar to G'(c)/G'(p), which is close to the electrical percolation threshold phi(1) and phi(2), respectively. Moreover, there exists phi-dependence of the dynamic loss tangent (tan delta) and a peak in plot of tan delta versus omega when phi approaches the loss angle threshold, phi(delta 1) (8 vol%). When phi > 20%, the second loss angle threshold, phi(delta 2), the tan delta shows almost no dependence on the GP content. phi(delta 1) and phi(delta 2) is Close to the electrical percolation threshold. A modified Kerner-Nielson equation was also obtained and used to analyze the formation of network structure in the matrix by substituting variable parameter K for constant A. The results indicate that the parameter K increases discontinuously with increasing phi, revealing this parameter is associated with GP concentration, and the critical threshold phi(K1) and phi(K2) is close to the electrical percolation threshold phi(1) and phi(2), respectively. Furthermore, the viscoelastic percolation for GP/HDPE composites can be verified on the basis of the modified equation. (c) 2006 Elsevier Ltd. All rights reserved.