Studies on thermal conductivity of single polymer chains have been of vital importance to improve thermal properties of bulky polymeric materials. In the present research, the thermal conductivity of high density polyethylene (HDPE) nanofibers was calculated using the Green-Kubo equilibrium molecular dynamics simulation method. Results suggest that the thermal conductivity of a polyethylene nanofiber chain is high (approximately 26 W/mK) at room temperature, and this reaches higher values when increasing the chain length, therefore this approach provides useful strategies to optimize the intrinsic thermal properties of polymeric nanostructures.