We studied vaccine strains of influenza viruses A and B during their culturing in MDCK and Vero cells grown in Eagle's MEM medium and in a medium on the basis of enzyme hydrolysate of rise flour proteins with reduced (2%) content of fetal calf serum. Optimal conditions for cell culturing and reproduction of influenza virus strains in these cells were studied. Culturing of vaccine strains of influenza viruses in MDCK and Vero cells grown in nutrient media on the basis of rise flour protein hydrolysate yielded high infection titers, which suggests that this medium can be used for the development of cultural influenza vaccine.