There are various models for oceanic removal of reactive elements of short residence time. Among them, a model proposed by Tsunogai and Minagawa (1978) appears to fit well recent findings from sediment trap experiments. The findings include that biogenic particles containing SiO₂ and CaCO₃ as major components reach a deep-sea bottom without serious alteration. Radionuclides of reactive elements such as Th and Pb in seawater and in particles indicate an active transformation of particles between large settling aggregates and small suspended particles including those passing through filter papers. Furthermore, increases with depth in fluxes of Al and of other metals and in the ratio of Mn/Al for settling particles in the world ocean suggest that horizontal diffusion and advection are strong. Also, small particles appear to regenerate enormously from large particles at sea-bottom interface, especially in shallow seas. While these findings agree with the model, they also make desirable for it to take into account horizontal motions of water and the particles and to extend to all chemical constituents in the ocean. Therefore, I here present a new model, "train-passengers model". The train is a rapidly sinking large aggregate particle, while the passengers are small particles of clay, oxides, hydroxides, insoluble organic molecules, etc. Further studies based on the new model can be planned to make quantitatively clear the behavior of chemical constituents in the ocean.