Using near-infrared spectroscopy and thermogravimetry coupled with differential scanning calorimetry (TG-DSC), we investigated the characteristics of water in starch and the effects of the inner structure of starch on dehydration. The results directly show that the dehydration process is significantly more favorable in native starch than in gelatinized starch. When the starch was heated to 100 °C, the water retention in gelatinized starch was 22.35 per total water content, much greater than that in native starch (4.3%). The hydrogen bond network that changes from native starch to gelatinized starch was simultaneously explored, and the weaker hydrogen bonds were found to be predominant in the hydrogen bond network of gelatinized starch.