Pulsed-field gradient NMR (PFG-NMR) is widely applied to probe living tissues and biological cells structure for measuring thermodynamic binding constants, membrane permeability and rates of transmembrane exchange processes. Water movements in biological systems and food matrices are important in the engineering aspect such as quality manipulation in food processing. The measurement of diffusion properties of water molecules in food systems is now possible using PFG-NMR, and the hydration properties and hydrodynamic properties of food materials can be accurately evaluated by this method. In this paper, we measured the diffusion behaviour of water in protein matrix, Tofu, and the membrane permeability in biological cell such as chlorella, yeast and human red blood cell non-invasively by PFG-NMR.