Abstarct: The water is restricted agent for growth and development for crops and development for crops and drought stress is a main agent of damages to crop in worldwide. Todays, polyamines including putricine (put), spermidine (spd),and spermine (spm) are organic polycations with low molecular weight that protect plants as regulators of physiological process against stresses. In order to evaluate the effect of spd on growth and some of characteristics of soybeanunder drought stresswas conducted an experiment with two stages including germination and seedling growth under experimental condition at Sari Agricultural Science and Natural Resources University and field experiment on soybean CV. Caspian in drought stress condition in 2016 and 2017 years in Mazandaran, Joybar. In germination experiment, treatments were including three level of drought stress (0, -2, -4 bar), and three level of spemidine (0, 1, 2 mM) with 4 replicatins. For condition drought stress is used PEG 8000. The results showed that application of spd at rate of 1 mM improved germination properties, significantly, including germination maximum, germination rate, germination uniformity,times 10, 50, 90% germination, radicle length,seedling weight and final germination under mild drought stress (-2 bar). High dose of spermidine couldnot improve the tolerance to intensive stress in evaluated traits the priming by spd led to increasing of tolerance to stress by improvement germination properties and increasing of activity of antioxidant enzymes in soybean seedlings. The field experiment was conducted baxsed on randomized complete block design with three replication in chapakrood (Joybar, mazandaran province) in 2016 and 2017 years. The treatments were included four irrigation levels (100, 70, 50 and 30% of waterrequrement) as main plots and three spd levels (0, 0.5, 1 mM) as sub-plots. Evaluated parameters were leaf number, pod number per plant, plant height, seed number per plant, weight of 1000 seeds, dry matter yield per plant, seed yield per plant, membrane stability index (MSI), relative water content (RWC), electrolyte leakage (EL), malondealdehyde (MDA), and hydrogen peroxide (H2O2), photosynthetical pigments(cholorophyll a, cholorophyll b, and carotenoids), amount protein of leaf, activity of antioxidant enzymes including CAT, APX, POD, and amount leaf proline were significant (p˂0.05). The results showed with decreasing amount irrigation, application of spd specially in middle and high stresses (irrigation low 50% water requirement) could increase plant tolerance to stress with improvement of evealuated characteristics and increasing of antioxidant enzymes..