Abstarct: Abstract With the global outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), researchers worldwide have been actively working on the development of new drugs and vaccines to treat or prevent the progression of this disease. Although no specific treatment has been introduced yet, there is a global need to identify new drugs for the treatment of this disease. Recent experimental findings have shown that certain herbal compounds such as Cordycepin, Crotonoside, and Hypoxanthine have significant clinical effects on human health and play an effective role in the treatment of this disease. In this study, the structural, electronic, and thermodynamic properties of the tautomeric forms of these compounds, as well as their binding affinity using quantum mechanical calculations baxsed on density functional theory at the B3LYP/6-31G (d) level of theory in both gas and solvent phases, were examined. The results indicate that the tautomeric forms of Cordycepin and Crotonoside are non-planar, while the tautomeric forms of Hypoxanthine are planar. Electronic property calculations, such as energy gap and dipole moment, show that the amino tautomer of Cordycepin, amino-enol and imino-keto tautomers of Crotonoside, and lactam tautomer of hypoxanthine exhibit greater stability. Furthermore, the thermodynamic results of the tautomeric compounds show that the amino form of Cordycepin and the lactam form of hypoxanthine in the gas phase, and the amino-enol and imino-keto forms of Crotonoside in the aqueous phase, are more stable, with the tautomeric process being spontaneous and exothermic. Kinetic calculations of the tautomeric process of forming the amino forms, amino-enol and imino-keto forms, as well as the lactam form, clearly demonstrate an increase in the rate of formation of these tautomers. The results of the energy calculations for the studied compounds with important RNA baxse pairs have shown that in the gaseous phase, the amino form complexes with guanine and the imino form complexes with cytosine have the most stable energy values for the coordination of cordycepin. The amino-enol complexes with guanine, amino-keto complexes with guanine, imino-enol complexes with uracil, and imino-keto complexes with guanine have the most stable energy values for the coordination of Crotonoside, and the lactam form complexes with guanine and the lactim form complexes with guanine have the most stable energy values for the coordination of hypoxanthine. It has also been observed that the energy values of the complexes in aqueous solvent differ from those in the gaseous phase. In general, all complexes are stable, and the occurrence of these baxse pairings is possible and can lead to the termination of the RNA replication chain and the formation of the COVID-19 virus.