Antitumor and antibacterial activity of complex preparations consisting of yeast mannan, diacetile-2,4-dioxohexahidro-1,3,5-triasine, cianohyanidine, alcansulfonic acids (emulsifier E-30), and microbial metabolites was studied. The investigation was carrying out on explants of tuber potato parenchyma infected by Agrobacterium tumefaciens. We found that preparations have the antitumor activity. The most activity was exhibited by addition of preparations to the cultural medium and treatment of explants before of infection.