Abstract Settling particles collected by sediment traps at four stations in the Pacific Ocean were analyzed for their Cd, Ni and Cu content. The vertical distribution of Cd concentration shows a rapid decrease with depth, and the spatial variation of Cd flux showed an increase with total particulate flux. On the other hand, spatial variation of Ni and Cu concentrations within settling particles was larger than their vertical variation. The larger the total particulate flux, the lower the concentrations of Ni and Cu in the settling particles. This is due to dilution by biogenic particles which contain less of these metals. These results reveal that these metals are carried down by at least two kinds of particles with different chemical and biological characteristics. One type are particles that are similar to non-biogenic inorganic particles. The other type are particles that originate in biological activity. Whereas Ni and Cu are carried from surface water to deep water by both particles, Cd is carried almost completely by the latter.