For several decades, sugar molecules, such as glucose and trehalose, have been shown to improve the freezing survival of animal and plant cells. The protective mechanism underlying this process has been identified from experiments and indicated that the water-replacement, water-entrapment, and vitrification processes are equally important in the stabilization of biological structures. At dehydrated conditions, sugar molecules preserve cells membranes by keeping them in their functional liquid-crystalline state. This is confirmed by recent experiments showing that the presence of sugar molecules alters the phase transition temperature from a gel to a liquid-crystalline phase of model cell membranes. However, it is unclear from these experiments the protective mechanism that link sugar concentrations, hydrating conditions, and phase transition temperatures. Here, we employ atomistic molecular dynamic (MD) simulations to investigate the effect of glucose and trehalose concentrations on DPPC bilayer structures below and at normal hydrating conditions. The simulations presented in this study will provide insight into how the molecular properties of the sugar molecules are associated with the changes to the DPPC bilayer phase transition temperature.