The effect of cytokinin, thiourea, and complex chemical Polyel + F on the ability of water status selfregulation, photosynthesis, and on the efficiency of water use by plants under conditions of humidity fluctuations and repeated drought was studied. Glycine max (Merr) L. plants of ‘Nadejda’, ‘Moldovitsa’ and ‘Magia’ cultivars grown in the Mitcherlih vegetation pots with a volume of 40 kg soil and exposed to the drought stress at the phases ”first trifoliate leaf” and ”flowering – pod formation” were used in the study. The studied compounds’ property to increase the plant resistance to unfavorable humidity fluctuations and conditions of repeated moderate drought has been established. Plants that have endured a moderate drought in the early stages of ontogenesis become more tolerant to moderate water stress during flowering and pod formation. The effect of tolerance inducing in plants pre-treated with respective compounds is manifested by increasing the water retention capacity, keeping the internal aqueous medium at a comparatively higher level. After restoring optimal moisture conditions, the plants pre-treated with thiourea and Polyel+F restore their functional processes more integrally. The research data suggest that changes occurring at the cellular level in the early stages of development, caused by moderate moisture deficiency and conferring resistance, are initiated when the water content decreases and can be consolidated when water loss is not too drastic.