3-Dimensional chitosan(CS)materials with high mechanical properties have been prepared via in-situ precipitated method．Owing to the existence of hydrophilie groups

the structure and properties of CS materials is easily affected hy the hydrated water．Water sorption in the CS material is Fickian in nature.Thermal analyses revealed the existence of up to three energetically distinct states of water：bound water

intermediate water and free water in the water saturated CS rod

each type of water have different effects on the mechanical properties of the material．Initially

there exists thermal stable bound water that can not be easily removed.Interaction between water and CS results in a strengthening of the hydrogen bond network．Subsequent absorbed intermediate water of CS material in the water environment acts as a plasticizer

forming water-water bridges that loosen the hydrogen bonding network．Modeling of the modulus and strength of CS rods with the Fermi’s equation for the fall in the modulus and strength as a function of warer content under isothermal condition was fitted．Differ to other CS blends

this intermediate water is non-freezing．In the later stage of water sorptiou

water enters the CS and loosely adhered as free water which is freezing

undergoes no thermal phase transition over the range of temperatures normally associated with bulk water

having few effects on the mechanical properties of the CS rod.