In this study enzymatic synthesis of gold nanoparticles was carried out using the reaction of the glucose oxidation catalyzed by glucose dehydrogenase (Gc GDH) and the cellobiose oxi-dation catalyzed by cellobiose dehydrogenase (Mt CDH). The kinetics of both enzymes were investigated in the above reactions and the influence of the gold ions on the enzyme activity was examined. Kinetics in both cases were described by one-substrate Michaelis-Menten ki-netics with competitive inhibition of gold ions. Estimated inhibition constant revealed signifi-cant inhibition of Gc GDH by gold ions in the reaction of glucose oxidation. By carrying out the synthesis of gold nanoparticles with cellobiose oxidation catalysed Mt CDH, it has been shown that the mechanism of nanoparticles formation is directly related with reaction kinetics. For this synthesis a mathematical model was set and it was in good agreement with experimen-tal results. The results of the synthesis of nanoparticles with Gc GDH and glucose showed that the nanoparticle formation mechanism is not related to the kinetics of the reaction. In this case gold nanoparticles were formed by the reduction of gold ions with glucose and protein i.e. enzyme amino acids. This was also confirmed in the control experiments.