Abstract: Dissolved inorganic nitrogen (DIN) is mainly composed of nitrite (NO^-₂-N), nitrate (NO^-₃-N) and ammonium (NH⁺₄-N), which plays an important role in the marine biogeochemical cycle. However, human activities have introduced large amount of inorganic nitrogen and caused many serious environmental problems. In order to study marine nitrogen cycle and manage environmental pollution, it is necessary to determine DIN in seawater. Among many analytical methods, spectroscopic method becomes the top choice for seawater DIN analysis because of good versatility, wide applicability and simple equipment. This review summarizes the research progress in the determination of DIN in seawater based on spectroscopic methods in recent ten years, including UV spectrophotometry for NO^-₃-N determination, N-1-naphthylethylenediamine dihydrochloride spectrophotometry for NO^-₂-N and NO^-₃-N determination, hypobromite oxidation and spectrophotometry for NH⁺₄-N determination, indophenol blue spectrophotometry for NH⁺₄-N determination, acid-base indicator and spectrophotometry for NH⁺₄-N determination, fluorescence and chemiluminescence for DIN determination. The characteristics of each analytical method are compared, and the developmental trend of seawater DIN analysis with spectroscopic method is prospected. In general, for analytical methods, the use of new reagents and the emergence of some new synthetic materials have enriched the analytical means of DIN. For analytical instrument, the instrument based on flow analysis technology is widely used in the laboratory and field analysis of DIN. The analysis methods of DIN are developing in the direction of simple and convenient, full automation, rapid analysis, high accuracy and wide range of application.