Abstract: Basalt fibers (BF) were surfacemodified by γ-aminopropyltriethoxysilane and Vinyl-triethoxysilane coupling agents and then added into wood fiber reinforced high density polyethylene (HDPE) composites to improve the mechanical properties of the later. The surface of basalt fibers were characterized by SEM and FTIR, and the effects of the basalt fiber content and micrographic fracture surface on the mechanical properties of the composites were studied. The results showed that BF modified by coupling agents could be better combined with HDPE surface due to the increased interfacial compatibility between BF and HDPE, the impact property of the composites was improved, the tensile strength of the composites was increased with the addition of BF treated by γ-aminopropyltriethoxysilane coupling agent and the flexure strength was promoted with the addition of BF treated by Vinyl-triethoxysilane coupling agent, respectively. The results indicated that the above properties of the composites could be significantly increased by adding 4% of the modified basalt fibers.