The results of comparative studying effects of 4-hydroxyphenethyl alcohol — exometabolite of purple bacterium Rhodospirillum rubrum and synthetic cytokinin 6-benzylaminopurine on seed germination, growth, productivity and development of amaranth vegetable form (Amaranthus caudatus L.) and also on the set of their physiological-biochemical parameters are presented. It was established, that seeds treatment with solutions of investigated substances (10-6 М) led to similar positive effects in all studied indices in the plants growing from these seeds. The authors suggest to use the 4-hydroxyphenethyl alcohol as the growth cytokinin-like natural stimulator for improvement of seed grain and plant productivity.