Abstract Electrochemical and dilatometric studies have indicated that at least three states of water exist in macromolecular gels. The properties of each state of water in gels such as agarose gels were investigated by highresolution and broadline PMR over the temperature range from +50 to −60°C. The linewidth of water protons in gels was found to depend markedly on the water content of gels, and the linewidth vs. water content curve gave two inflection points. One of the inflection points can be attributed to the so-called bound water, but the other cannot be explained unless three states of water are assumed in gels. Three kinds of transition temperatures were confirmed by anomalous changes in the PMR linewidth below 0°C. The so-called bound water exhibited no transition temperature between 0 and −20°C, and free water gave the transition temperature at 0°C. Moreover, the transition temperature of a quantity of water was distributed in the range from 0 to −20°C. On the basis of the transition temperature, the properties of water in macromolecular gels are discussed.