Abstract: Amino acids, as one of the most important readily bioavailable components in marine organic nitrogen pool, have attracted more and more attention with the deepening understanding of the biogeochemical cycle of organic nitrogen in the marine environment. Studies on composition and bioavailability of amino acids are of great significance to understand the migration and transformation of organic nitrogen in the ocean. In this paper, the advances in analytical methods for dissolved amino acids in seawater, such as spectrophotometry and fluorospectrophotometry and separation methods, such as ion exchange chromatography (IEC) and high-performance liquid chromatography (HPLC) are detailed explained. And the most widely used precolumn derivatives-reversed-phase liquid chromatography-fluorescence detection method is more detailed reviewed. Moreover, the latest techniques such as mass spectrometry (MS), compound-specific isotope analysis (CSIA) and capillary electrophoresis (CE) are also mentioned, as well as their prospected applications in oceanography.