Identification of the Structural and energetic determinants responsible for enhancing the stability of proteins is Crucial. Hyperthermophilic proteins are naturally Occurring proteins that exhibit high thermal stability and are good candidate for the investigation and understanding of structure-stability relationships. Sac7d from Sulfolobus acidocaldarius and Sso7d from Sulfolobus solfactaricus Lire two homologous hyperthermophilic proteins that were shown to be quite stable Lit high temperatures. Molecular dynamics simulations at the nanosecond time scale Lit different temperature, were performed to examine the factors affecting their stability. The three-dimensional Structures of these proteins were observed to be similar to the experimental structure at 300 and 360 K but were found to Undergo denaturation at 500 K. Both proteins exhibit similar unfolding Pathways that correlates well with the calculated intermolecular interaction energies. The differential dynamic behaviors of these molecules Lit different temperatures were examined. Structural and energetic analysis of the contributions of salt bridges indicates a stabilizing effect at higher temperatures. However, the lifetimes of the salt bridges were found to be quite short, and several new salt bridges formed at 500 K supporting previous studies that the desolvation penalty due to the formation of salt bridges decreases at elevated temperatures. Hydrophobic interactions, which decrease with increase in temperature, were also found to be crucial in the stability of these proteins. Overall, the Study shows that a balance among the salt bridge interactions, hydrophobic interactions, and solvent properties is primarily responsible for the high thermal stability of this class of proteins.