To get some insight into the mechanisms of cryopreservation that characterize disaccharides, and to clarify the reasons that make trehalose the most effective bio-protector, we report measurements on trehalose, maltose, and sucrose aqueous solutions. To analyse the interaction mechanisms of the three homologous disaccharides with water, we have investigated the volumetric properties of the three disaccharide solutions, by performing density and ultrasonic velocity measurements at different concentration and temperature values. In addition, we analyse the thermal properties of trehalose, maltose and sucrose aqueous solutions by using Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). What emerges from these studies is that trehalose shows, in comparison with maltose and sucrose, the smallest values of the partial molar volume in all the investigated temperature range, this circumstance being indicative of a more packed conformational arrangement especially at the lowest temperatures. Furthermore, trehalose reveals, in respect to the other disaccharides, the greatest structural sensitivity to temperature changes. Finally, calorimetric measurements indicate a greater effectiveness of trehalose in destroying the tetrahedral network of water compatible with the formation of ice, supporting the hypothesis of a higher “fragile” thermodynamic character of the trehalose-water system at high dilution. Preliminary TGA and DTG findings reveal a noticeable stronger trehalose-water interaction mechanism and a significant higher thermal stability of the trehalose system.