The thermal behavior, structure, and dynamic properties of water confined in polymer gel Sephadex G15 were investigated over a temperature range of 298-173K as a function of hydration level (g H₂O/g dry gel) by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and quasi-elastic neutron scattering (QENS) and neutron spin echo (NSE) measurements. The DSC data showed that there are three states of water in G15 gel: free water, freezable bound water, and unfrozen water. The X-ray radial distribution functions revealed that the tetrahedral-like hydrogen bonded network of confined water is largely distorted, compared with the bulk water. The QENS data showed that the water molecules perform local motions characterized by a diffusion coefficient of (0.65±0.05)×10^-5cm²s^-1 within a sphere with a radius of 4.4 Å. The Arrhenius plots of the relaxation time of water gave an activation energy of 44.2±1.5 kJmol^-1, which is somewhat larger than the value of 15-36kJmol^-1 of capillary condensed water confined in mesoporous silica MCM-41 C10 (pore diameter 21 Å). The present findings suggest that water molecules in G15 gels are strongly bound to the hydroxyl groups of the gel matrix.