The paper aimed to present the results of studying the administration of algal bio-fertilizers to cultivation of tomatoes (Lycopersicum esculentum L.) under greenhouse conditions. In the experiments were involved algae cyanophytes Anabaena variabilis and Nostoc gelatinosum, which are deposited in pure collection in laboratory of “Phycology”. During the experiments was monitored soil pH, plant growth, the productivity of tomatoes and the total N from soil layer. Administration of algal bio-fertilizers Anabaena variabilis ensures the accumulation of more high levels of nitrogen in the soil, compared to other experimental variations. Bio-fertilizers administration contributes to stimulating growth of the stem height of tomato plants, increasing the number of seedlings of tomato to a 1 to 2.30 times and productivity tomatoes from 1.73 to 3.40 compared to the group in which was not given algal biomass. The highest results of tomatoes productivity were attested in variant with administering bio-fertilizers based of Nostoc gelatinosum biomass.