With freshwater getting scares seawater, i.e., water containing NaCl, can become the only viable option for making concrete. Although a lot of research had been directed to understanding the role of water in cement hydration, not much is known about the interaction of the Na+ and Cl- with cement paste during drying. A problem is that available techniques like, i.e., XRD, SEM, and EDX, for measuring the microstructure and the methods for determining the concentration of Na+, Cl- ions in pore solutions are either indirect or invasive and moreover often destructive, which consequently may lead to inadequate interpretations. Using a specially designed Nuclear Magnetic Resonance (NMR) setup, the 1H, 23Na and 35Cl content in cementitious materials can be measured quasi-simultaneously and hence give us direct information on the interaction of the ions and the microstructure development. We have studied the influence factor, i.e., the water-cement ratio, on the microstructure development and the binding of Cl- and Na+. It was found that during the initial hydration stage more Cl- is bound in comparison to Na+ . This is reversed during the acceleration period after which there is a preference for binding of Na+ in comparison to Cl-. Increase of W/C ratio results in less binding capability of Na+ and Cl-.