A differential scanning calorimeter was used to study the glass transformation of glycerol-H2O-NaCl ternary system and glycerol-PBS complex system that are used clinically in order to explore the cryoprotective role of glycerol in preserving frozen biomaterials. These systems are of particular importance in the field of cryobiology, for knowledge of glassy phases may be especially crucial for long-term cryopreservation of biological materials. The melting and glass transition temperatures for the two systems of different concentration (glycerol, mass concentration, from 5 to 100%, interval 5%) were measured, and very simple equations have been derived for predicting the temperatures. A glassy state that is crystallographically amorphous was found for glycerol concentration between 45 and 60%, and a complete glassy state was found at glycerol concentration greater than 60% for both of the systems. These supplemented phase diagram data may help the design of procedures during vitrification preservation process based on glycerol. (C) 2004 Elsevier B.V. All rights reserved.