Abstract: PVA hydrogel artificial nucleus materials were prepared by a freeze-thaw cycle method, their compressive creep properties and viscoelastic model were studied in deionized water and different simulated body fluids, including saline and Hanks solutions. PVA hydrogel exhibits very good viscoelastic properties in the different simulated body fluids, the speed and deformation to reach the creep equilibrium are related to ion content in the fluids. Isochronous lines show that the mechanical behavior of PVA hydrogel accords with the linear viscoelastic behavior. The Kelvin-Voigt model succeeds in simulating the creep behavior of PVA hydrogel. Fitting results show that some salt ions in the body fluid inhibit the movement of small-size cells inside of PVA hydrogel, thereby extending the creep equilibrium time. Na⁺ in the body fluid can promote the movement of large-size cells inside of PVA hydrogel and makes it quickly to reach the creep equilibrium. These meet the clinical requirements.