Multiwalled carbon nanotubes (MWCNTs) were incorporated in low density polyethylene (LDPE)/ polyolefin elastomer (POE) (mass ratio: 70 : 30) blends by melt compounding. The morphology, electrical, mechanical and rheological properties as well as crystallisation behaviour of LDPE/POE/ MWCNTs composites were studied. The dispersion of MWCNTs in the matrix was observed by scanning electron microscopy. MWCNTs had a nucleating effect on LDPE/POE blends without influencing the crystal structure of composites, as shown by X-ray diffraction. The network of MWCNTs formed with the increasing content of MWCNTs, leading to the change in electrical resistivity and decrease in melt flowrate. There was percolation threshold existed in electrical resistivity. As content of MWCNT was 10 wt-% in composite, the volume and surface resistivity of composites largely decreased; meanwhile, the dielectric constant of composite increased dramatically. The mechanical properties of composites decreased as the content of MWCNTs increased.