Biotechnology development prospects are intercorrelated with studies of enzymes – protein biocatalysts showing unique sensitivity and specificity of sharp demand in clinics, various industries and agriculture. Glucose oxidase (β-D-glucose: O2-1-oxidoreductase, E.C.1.1.3.4) catalyzes oxidation of βD-glucose to β-D-glucose-δ-lactone and hydrogen peroxide using molecular oxygen as electron acceptor. Glucose oxidase is indispensable in medical practice. Stability and high specificity of action make it an ideal object for enzymatic glucose determination method and application in sensor technologies used for express assays of carbohydrates and analytical control of bioprocesses. Therapeutic role of glucose oxidase was demonstrated for treatment of fresh and infected words, burns, frost injuries, stomatitis, and pyo-inflammatory skin diseases. The enzyme is applied in chemical industry to manufacture gluconic acid, gluconates, hydroquinone, propylene bromohydrine and in food processing as the preservative agent. Active glucose oxidase producers are filamentous fungi, especially representatives of genera Aspergillus and Penicillium. The cultures A. niger, P. amagasakiense, P. vitale are used for largescale production of enzyme preparations. Nowadays glucose oxidase investigations are carried out at various research centers in UK, Germany, Greece, Italy, Russia, USA, France, and Japan. The studies are mainly focused on seeking novel superactive sources of extracellular glucose oxidase, deciphering mechanisms governing enzyme synthesis, characterizing physical-chemical properties of biocatalysts, locating new application areal. Earlier highly active P. adametzii strain – glucose oxidase producer was selected at laboratory of enzymes, Institute of microbiology, NAS of Belarus. Aim of this research is to evaluate effect of ethanol on fungal biosynthesis of glucose oxidase and to assess stability of the enzyme. The fungus in liquid nutrient medium of optimized composition with addition of 0.5-2.0% ethanol was grown. It was established that under conditions of ethanol stress hydrophilic spores over hydrophobic ones predominated. Increasing of ethanol concentration leads to decrease of ability of fungal spores to aggregation. Ethanol affected on accumulation of fungal biomass too. Using 0.5-1.0% ethanol the level of extracellular glucose oxidase synthesis was increased by 1933% but further increase its concentration (to 2%) leads to decrease this indicator by 44%. The addition of ethanol influenced on final pH of medium. It was declined by 5.0-6.0%. At the next stage, thermal stability of glucose oxidases synthesized by the strain under ethanol stress was tested. The thermal stability was evaluated by residual activity and inactivation constants of enzyme solutions after 15-60 min of heating at 40 and 50°C (0.1 M phosphate buffer pH 3.5). It was found that all enzymes did not differ after hour incubation at 40 C, the residual activities of glucose oxidases were 6.5-19.4%, the inactivation constants were 0.0005-0.0008 s-1. After 50°C hour incubation the residual activity (1.5%) was retained only in the control variant. The obtained under conditions of ethanol stress (0.5-1.0%) enzymes lost their activity after 15-30 minutes completely. The inactivation constants of these glucose oxidases were 0.0051-0.0052 s-1. This was in 2.8 times more than in control variants. Thus ethanol stress affected on fungal sporogenesis, level of extracellular glucose oxidase biosynthesis and stability of the enzymes at 50°C.