Abstract: Sampling of surface seawater, ice and runoff were carried out during the Arctic scientific expeditions in July in 2010, which was organized by Beijing Teenager Science and Technology Club. The study area was coastal waters of Greenland, Svalbard and Iceland. The water quality analysis results showed that F^- and NO₃^- were not detected. Concentrations of macro-components in seawater were sequenced as Cl^- > Na⁺ > SO₄^2- > Mg²⁺ > K⁺ > Ca²⁺, which was accordant with general seawater. The ratio between concentration of all ions and chlorinity followed the Marcet-Dittmar Constant Ratios Law which testified that Greenland Sea was mainly recharged by precipitation and runoff from mainland. Ion concentrations in seawater of inshore were much lower compared with that of offshore because surface seawater was recharged by runoff resulted from glacier melting. Despite NO₃^- was detected in runoff at Svalbard, the coastal seawater samples were determined without NO₃^-, which indicated that the NO₃^- in runoff was sufficiently diluted under the effect of ocean current.