The main objective of the studies developed in this work was to verify the influence of the variation of the niobium concentration as binder on the mechanical properties, wear resistance and thermal stability of the polycrystalline-niobium diamond system prepared by HPHT. This compound has great applicability in several areas of engineering, such as aeronautics, civil, metallurgical and even in drilling. The studied concentrations of niobium were 2.5%, 5.0% and 10%.High energy grinding in Spex type mill was used to reduce the initial particle size of the PCD and for its mixture with the niobium, the effects of reduction of the average particle size verified were to values of 35.01 μm, 32.91 μm and 31.91μm (for, respectively, the concentrations of 2.5%, 5.0% and 10% of niobium as binder). The HPHT conditions used for the consolidations of cylindrical samples 5mm in diameter by 5mm in height were the temperature of 1750 ° C, the pressure of 7.7GPa and three cycles of 3 minutes. The density values obtained were about one hundred per center, with no porosity in the samples and no graphitization effects were observed. For the PCD with concentrations of 2.5%, 5.0% and 10% of niobium as binder, density values of 3.72 g / cm³, 3.81 g / cm³ and 3.90 g / cm³ and elasticity moduli of 946GPa, 998.4GPa and 1196GPa. Good dispersion of the metal phase was observed both on the surfaces and inside of the specimens, and it was also observed that the increase in the amount of binder allowed a greater tendency to the occurrence of intergranular rupture than to the cleavage. The tribological tests on pin-on-disc apparatus with a load of 150N and rotation of 500rpm allowed to observe that, when interacting with steel (with abrasion being observed as the predominant mechanism of wear), the wear trend is higher than in the case of its interaction with aluminum (where the great occurrence of adhesion is seen). The concentration of 10% of niobium as binder ensured lower wear resistance of the compound than that of 2.5%, in addition also higher values of temperatures were observed in regions close to the contact of the tribological pair, which are justified by the greater metallic interaction and by the decrease of the hard phase of diamond PCD.