Determination of soluble protein amino acid content isolated from bird cherry leaves during the spring development (April-May) was done using of ion-exchange chromatography. The fifteen amino acids were identified and determined. It was affirmed that valine was predominant among the all studied amino acids. Obtained results indicate that during spring maturing of bird cherry leaves increases the soluble protein concentration and total amino acid content of analysed protein fraction. It was shown the occurrence statistically significant seasonal changes in the content of ten amino acids: aspartic acid, glutamic acid, lysine, phenylalanine, leucine, isoleucine, tyrosine, methionine, threonine and serine.