Entomopathogenic fungi Beauveria bassiana (Bals.) Vuill. play an important role in controlling insect pests. In the investigations 37 strains have been used through isolation from natural population of B.bassiana fungus which in its turn was isolated from infested and dead samples of sucking pests of greenhouses. These strains of entomophatogenic fungus were grown under sterile condition in Petri plate and test-tubes with nutrient media. Abundant and fast formation of entomopathogen fungus conidia was observed mainly in the strains inoculated potato peptone nutrient medium. It was identified that conidia titer that was formed in B.bassiana fungus in nutrient media showed 32,4·106 cfu/ml in beer wort, in Chapek 15,7·106 cfu/ml and in potato peptone 68,9·106 cfu/ml.