This paper presents results of a study on the mechanical characteristics of impregnated Jabon wood (Anthocephalus cadamba) using Merbau extractives (ME) and two types of polymerised Merbau extractives (PME), i.e PME22 and PME33. A set of tests on hardness,  shear, modulus of elasticity (MOE) and modulus of rupture (MOR) was conducted according to the relevant standards. Two types qualitative analysis by means of FTIR spectra and XRD analysis were carried out to explore relationship between the mechanical characteristics alteration with physico-chemical characteristics. The results indicated that a positive improvement in mechanical characteristics was obtained for Jabon wood impregnated with PME22 and PME33. Surface hardness of modified wood samples exhibited higher values compared to the non-impregnated samples for end and side hardness, by 20.04 and 30.54 % (PME22), and 32.73 and 39.89 (PME33), respectively. Shear strength increased by 41.87 and 49.58 % (PME22) and 74.02 and 79.10 % (PME) for radial (T) and tangential (T) sections, respectively. MOE increased by 23.52% (PME22) and by 40.12% (PME33), MOR values also increased by 28.50 and 41.19 % after impregnation with PME22 and PME33, respectively. The increment of mechanical propertiesof treated Jabon wood after impregnation treatment using polymerised Merbau extractives were confirmed by FTIR spectra and crystallinity (XRD) analysis.