The article deals with the study of photomorphogenesis of different cucumber varieties under light culture conditions. Studies were carried out under laboratory conditions using an experimental phytosystem ESCO based on narrow-band light-emitting diodes, which is equipped with a microcontroller. The microcontroller controls the supplementary light modes. Studies were conducted to develop recommendations for selecting and controlling the spectral composition of light optimal for the life cycle of plants. The aim of our research is to study photomorphogenesis of different cucumber varieties under light-culture conditions using an experimental ESCO phytosystem based on narrow-band light-emitting diodes equipped with a microcontroller that controls the supplementary light modes. Four cucumber hybrids were used to test the ESCO phytosystem. Phytolamps were placed at the height of 1 m in the beginning, then at the height of 1.2 m. Every day we recorded the growth of shoot length, establishment of generative organs (flowers), we recorded the date of flowering and fruit formation. Conditions of humidity, nutrient and air regimes corresponded to biological requirements of growth and development of cucumber plants. Studies have shown that laying of generative organs of cucumber with additional lighting with narrow-band light emitting diodes is good. Female flowers appeared 7-14 days earlier in BV700+RV350+ BF350+FRF350 regime than in plants grown under natural light. The RV light regime had a significant effect on the increase in plant height. Determination of chlorophyll content showed its optimal amount and depended on the varietal characteristics of plants. The best supplementary light mode was BV700+RV350+ BF350+FRF350 during the cultivation of seedlings of different cucumber hybrids. Mode change all to 500 after planting in the ground.