In this work, 54 new homogeneous and mixed-ligand coordination compounds of magnesium and calcium nitrates were synthesized. Their individuality and coordination of ligands and nitrate anions to the central ion were determined by X-ray phase analysis and IR spectroscopy. The crystal structure of the coordination compound [Ca(NO3)2(NC5H4CONH2)2(H2O)2] was determined by X-ray diffraction analysis for the first time; the products of thermolysis were identified and the thermal properties of the synthesized compounds were determined. Energy parameters, charge distribution on atoms, geometry and reactivity of the synthesized compounds were determined by quantum-chemical methods. On the basis of biological activity analysis, a new stimulant for agricultural plants, Ca(NO3)2-CO(NH2)2-CS(NH2)2, was identified in a series of synthesized compounds. Application of the preparation resulted in acceleration of germination time, shortening of vegetation period and increase in cotton yield.