Nuclear magnetic resonance (NMR) spectrum of the short-lived nucleus 17N (I = 1/2, T1/2 = 4.17s) in liquid water was measured by means of the β-NMR technique to clarify the chemical species formed by nitrogen ions injected into water. We have improved the spectral resolution to 5ppm in the full width at half maximum which is about 1/40 times compared to the previous study. The shape of the obtained spectrum indicated that it may consist of multiple resonance lines rather than a single line. Some possibilities regarding the chemical states of nitrogen in water are discussed based on the present result.