In this study, HDPE/expanded graphite electrically conducting composites were prepared in the presence of expanded graphite (EG) via a melt-blending process. The microstructure, electrical, mechanical and thermal properties of the resulting HDPE/EG composites were investigated. The experimental results revealed that EG could be dispersed in the form of nanosheets in the HDPE matrix. The composite exhibited a low percolation threshold (phi(c)) of about 10.0 wt%, due to the high aspect ratio (width-to-thickness) of graphite nanosheets. With increase of EG content, the conductivity increases, while the tensile strength, elongation at break and impact strength decrease. When EG content reaches 30.0 wt%, the conductivity is about 3.5 x 10(-2) S/cm, the tensile strength, elongation at break and impact strength remain at 23.1 MPa, 76% and 5.7 KJ/m(2), respectively.