The azeotrope which an aqueous 1,4-dioxane solution shows at wide-ranged mixture mole fraction is supposed to result from the co-existence of water and 1,4-dioxane in the solution. The present study investigates the state of both components of the solution and control of the liquid structure of water by 1,4-dioxane and uses O-17-NMR chemical shift to perform a quantitative evaluation of the process by which hydrogen bonds are broken. The following conclusions are obtained: 1) The addition of 1,4-dioxane, which is capable of breaking hydrogen bonds, can be used to effectively control the liquid structure of water. 2) The process by which hydrogen bonds are broken can be evaluated quantitatively using O-17-NMR chemical shift.