Quercus petraea, a native tree species belonging to the regional flora of Baia Mare area, was tested for its resistance to heavy metal pollution in combination with systems composed of microorganisms amd bentonite. Native strains of microorganims (Aspergillus niger, Sarcina flava), from the flotation tailings of Bozanta Mare tailing pond were isolated, cultured and concentrated, and then used in pure cultures or in combination with bentonite. The strains of microorganisms, and the mixture of microorganims with bentonite, respectively, were included in the substrate of Quercus seedlings roots, the subjected to artificial pollution of Cd and Cu ions. It measured the concentrations of metal ions in the seedlings of different plant organs of experimental variants. Related to witness without any microorganisms or bentonite, the system bentonite-Aspergillus induced a decrease in the Cd concentrations in roots with 84.53%, in stem with 99.65% and in the leaves with 99.77%. The mixed system consisting in bentonite and bacteria drastically reduces copper availability for the plant. Use of this ”material” significantly reduces the concentration of Cu in plants with: 89.2% in the root, 79.69% in the stem and 90.86% in the leaves.