Low-field　nuclear　magnetic　resonance　(LF-NMR)　is　a　useful　method　in　studying　the　water　distribution　and　mobility　in　heterogeneous　systems.　This　technique　was　used　to　characterize　water　in　an　oat　β-glucan　aqueous　system　during　cryogelation　by　repeated　freeze-thaw　treatments.　The　results　indicated　that　microphase　separation　occurred　during　cryogelation,　and　three　water　components　were　determined　in　the　cryostructure.　The　spin-spin　relaxation　time　was　analyzed　on　the　basis　of　chemical　exchange　and　diffusion　exchange　theory.　The　location　of　each　water　component　was　identified　in　the　porous　microstructure　of　the　cryogel.　The　pore　size　measured　from　the　SEM　image　is　in　accordance　with　that　estimated　from　relaxation　time.　The　formation　of　cryogel　is　confirmed　by　rheological　method.　The　results　suggested　that　the　cryogelation　process　of　the　polysaccharide　could　be　monitored　by　LF-NMR　through　the　evolution　of　spin-spin　relaxation　characteristics.　©　2015　American　Chemical　Society.