It was studied the influence of the new synthetic cytokinins: 1,4-dihydroxy-phtalazine biguanidine salt (Sz-11) and N-isopropyl-benzimidazol chloride (Sz-28) on tissue culture of Lobelia inflata L. The tissue culture growth and also the level of producing by them alkaloids (lobelin within it) were the highest in concentration 1 mg/l of above cytokinins. In this concentration they showed the higher activity in comparison with kinetin. The addition of phenylalanine and lysine to the medium containing studied cytokinins increased the development of Lobelia inflata L. tissue culture and also stimulated their alkaloid production.