The subject of our analysis was a micro-culture of 3 fungi species: Fusarium sp.: Fusarium culmorum, F. graminearum, and F. avenaceum. The analysis was performed in an automated apparatus ‘Bioscreen C’. In the cultures investigated, the effect of G. candidum yeast metabolites on the growth of the Fusarium fungi was studied and assessed. The yeast metabolites were obtained from a culture of these yeasts with Fusarium biomass added to the medium. In order to differentiate protein and non-protein metabolites, two types of supernatants were added: one group of them was not inactivated, and the second one – inactivated over 20 minutes at a temperature of 95oC. It was proved that the G. candidum metabolites studied were antagonistically active towards the 2 species: F. culmorum, F. graminearum, and that they were stimulatingly active towards F. avenaceum. The yeast metabolites prolonged the time of fungal spore germination (lag-phase) up to 34 hours comparing to the control culture (with no supernatants added). Additionally, the biomass yield was essentially decreased in the cultures containing metabolites of yeasts. In the presence of metabolites, the stimulated strain (F. avenaceum 1) grew faster (to 60%) and more effective (to 25%) than in the control culture. The inhibiting effect of supernatants could be attributed both to the presence of active metabolites in them, and to the enzymes produced by yeasts.