Olive (Olea europaea L.) is an evergreen tree extensively cultivated for its fruit in many warm parts of Southern Europe, North Africa, South Asia and Oceania. The objective of this paper was to obtain information on the total biomass productivity of the olive grove as well as on individual tree biomass productivity and the proportions of the tree components. The study was carried out in Central Italy and estimation of tree woody biomass and total biomass was made by direct measurement and through Intergovernmental Panel on Climate Change (IPCC) methodology. To determine the biomass of all the tree parts (including fruits and prunings) of the olive grove, the forestry estimation methodology named “model tree” was adopted and one representative tree was felled and uprooted; the biomass of main trunk, branches, leaves, twigs and roots was determined separately, using their volume, weight and density; also fruits and prunings of this tree were recorded. Wood density, biomass expansion factor, root/shoot ratio, carbon fraction of dry matter and carbon content of the single tree and tree component were calculated. The study showed that “model tree” methodology is suitable for olive grove; IPCC method can be successfully used with good reliability when direct measurement of biomass expansion factor and carbon fraction are obtained from a representative tree of the olive grove. The C stock evaluation methodology made in this research and the calculation of biomass expansion factor can be considered as the first scientific contribution in estimating productivity, CO2 sequestration, carbon stocks and yield of olive groves.Key words: Biomass, biomass expansion factor, Intergovernmental Panel on Climate Change (IPCC), tree volume, root/shoot ratio, Olea europaea, CO2 sequestration.