Abstract: Anion exchange method is investigated to separate and enrich iridium in seawater by radiotracer~(192)Ir.The adsorption of Ir in the resin increases with the decreasing acidity in the 0.05～1.2 mol/L HCl media.The recovery of iridium in pH=1.5 seawater reaches 89% by a single anion-exchange column.The polyethylene contrainer of acidity of pH=1.5 are suitable for storing trace Ir in seawater.An anion exchange preconcentration-neutron activation analysis procedure is developed to determine (iridium) in seawaters sampled from the Bering Sea and Arctic Ocean at different depth.The reagent blank value of the whole procedures is (0.18～0.20)×10~(-12) g Ir.The iridium concentrations in the Bering Sea and Arctic Ocean seawater samples are (0.85～3.58)×10~(-12) g/L (0～3 504 m) and (1.26～1.97)×10~(-12) g/L (25～1 900 m),respectively.