In this study the effects of fibre loading and coupling agent on the performance of Empty Fruit Bunch (EFB) fibre composites of oil palm biomass were investigated. The dried EFB were ground in random sizes for composite production. Ground fibre was compounded with polypropylene (PP) by means of a twin-screw compounder for preparing of EFB/PP composites. Maleic anhydride grafted polypropylene (MAPP) was used as a coupling agent. The incorporated fibre contents for EFB composites were 10 to 40% (by weight). The test specimens were prepared by injection moulding. The composites were characterized by melt flow index, mechanical tests such as tensile strength (TS), tensile modulus (TM), flexural strength (FS), flexural modulus (FM) and impact strength (IS). Surface morphology was also studied by SEM. Bonding/interaction mechanism was studied by FTIR and thermal stability was studied by TGA analysis form where the activation energy was calculated for different composites. It was found that both coupling agent and fibre content play in important role on composites properties.