Water mixture with tert-butanol shows two critical points if the logarithm of dielectric relaxation time is plotted against the mol fraction of water X(W). One point at X(W) approximately 0.97 is suggested to indicate the break point of a high order structure of water and another point X(W) = 0.83 is that of a local structure. Existence of the high order structure was already indicated by a recent dielectric study on water-glucose mixture. The structure is a less ordered lattice of ordinary ice type. It is also shown that water mixture with treharose or maltose exhibits one relaxation peak as well as the glucose mixture. This manifests that the diameter of the water cluster is nearly the same as the length of treharose or maltose, at least, smaller than that of maltotriose which shows two relaxation peaks. The critical point X(W) approximately 0.97 corresponds to about 30 water molecules included in the high order structure, which is very reasonable to compare the result of the glucose mixture.