Drought, which is increasing day by day with the effect of global climate change, is one of the most common environmental stresses that prevent the growth and development of plants and reduce the yield and quality of crops. Polyamines are growth regulators that play a role in the physiological processes, development and defense mechanisms of plants against environmental stresses. Therefore, in this study, the effect of exogenous application of Spermine (Spm), an important polyamine species, on biochemical and molecular properties of Hordeum vulgare cv. Burakbey plant under both normal (distilled water) and drought stress (PEG 6000) was investigated. Plant samples were divided into sections such as Group I (distilled water), Group II (distilled water + 10 mu M Spm), Group III (-6,30 mPa (megapascal) PEG 6000) and Group IV (-6,30 mPa PEG 6000 + 10 mu M Spm). In the sample of the third group, drought stress negatively affected plant growth and development by causing changes in the content of all parameters examined. Exogenous Spm application in the second group affected plant metabolism negatively in many parameters by causing changes in the investigated parameters, although not as much as drought stress. In other words, exogenous Spm given in a stress-free environment has an effect like low impact drought stress. In the fourth group plants, it was determined that the exogenous Spm application had a curative effect on the cell cycle, total protein content (12%), MDA (78%), and APX (15%) levels compared to the third group plants. Exogenous Spm administration in the same group did not decrease SOD (25%) and CAT (78%) enzyme levels, but also increased them even more. In the light of all parameters, it is thought that applying exogenous Spm with the appropriate time and dose can greatly alleviate the negative effects of drought stress on plant growth and development, and it can be very beneficial for plants that can grow in arid lands.