Abstract: While amino acids balance the metabolic pathway in plants and soil by activating / inhibiting enzymes, they also produce protein-rich foods to meet the needs of the body and provides resistance to stress conditions such as high temperature, low humidity, frost, insect damage, hail damage and flood which reduce the quality and quantity of the product and has a negative impact on plant metabolism. In addition, the application of amino acids before, during and after the occurrence of stress conditions has the effect of preventing and improving problems in stress physiology. In this context, aqueous solutions of amino acids in different concentrations were prepared in research by using phenylalanine, tyrosine, arginine and methionine as amino acid types and applications were made on cucumber (Cucumis sativus L.) plants grown in ecological conditions of Düzce region. These studies were carried out under greenhouse and controlled conditions (temperature, humidity, light). After growing plants, macro and micro nutrients obtained from leaves and soil samples were examined. IR analysis was performed to determine the general content of the samples taken from the plants. As a result of the research, transportation of anionic and cationic plant nutrients from soil to plant or from plant to soil by means of amino acids was achieved. However, since the amino acids are in dipolar structure and provide the possibility to carry both anionic and cationic plant nutrients simultaneously, development process of plants shortened and their effects on the agricultural properties of plants were found to be positive. It was seen that protein content can be increased significantly by the application of amino acid, which is the building block of protein and that its effects on agricultural properties of plants can be positive.