REEs and Y, in general, increase in concentration with depth. Heavy REEs reach a maximum concentration at about 2000m and then decrease or keep constant to the bottom, while light REEs continue to increase in concentration with depth. The shale-normalized REE patterns, as studied by previous workers, show enrichment of heavy REEs over light REEs, which is conventionally interpreted as a result of strong complexation of heavy REEs relative to light REEs in seawater. Middle REEs show slight depletion relative to both light and heavy REEs in deep water. The first detailed depth-profile of Y(III) presented here in seawater with the lanthanide in the North Pacific provides significant insights into the comparative behaviors of Y and REEs in seawater. The concentrations of Y range 70-290 pmol/kg and show the “nutrient-like” profile best resembling that of H₀ amongst the other REEs, in agreement with an expectation based on the similarity in their ionic radii and hence stability constants of complexation with carbonate ion. Yet variation of H₀/Y ratios in seawater reflects a difference in complexation of Y and H₀ with soft organic ligands on the surface of particulate matter during scavenging and the movement of water mass.