Abstract: Hemoglobin is a tetrameric protein of α2β2 subunits. The main function of hemoglobin is to pick up oxygen from surrounding environment. Since oxygen solubility in water is very low the availability of dissolved oxygen is affect by different factors e.g., temperature, salinity and pH. Temperature increment accounted as a more threatening factor for fish in regions with hot climate. In the present work, through conducting different experiment and using different methods such as circular dichroism, differential scanning calorimetry we decided to study hemoglobin stability against temperatures. Barbus sharpeyi was used as a model habitat in hot climate. Our results show that Barbus sharpeyi hemoglobin shows high melting high transition temperature of 68°C which tolerate against thermal denaturation for long period. The wide transition range of 56-68°C indicates that B.S. can adapt and survive in hot climate unexpectedly.