Abstract: The content of water in freezed-dried red bolld cells, which influence on the function of red blood cells after rehydration is an important specification.It is diffiant to separate and determine precisely because water and samples were mixed and incorporated. The content of water was gained by routine proton NMR integration combined with the method of standard addition, after water in samples was completely absorbed by d₆-acetone, which is soluble in water in all proportions. The result showed that this approach is simple, easy and accurate.

Key words: Standard addition, Freezed-dried red cells, Content of water, Proton NMR