Rare Earth Elements (REEs) which form a coherent group of trace elements whose chemical properties change systematically across the series (La through Lu) are generally used to understand and investigate the geochemical processes of coastal and estuarial areas, which can be employed as geochemical tracer. In this paper, the reviews of separation, preconcentration, and determination of trace rare earth elements (REEs) in estuarine water and seawater, as well as the approaches of REEs geochemical studies in coastal and estuarial areas and the interactions of REEs between water, suspended particle matter, and sediment in these areas are included. The trend of REEs geochemical research and possible investigation in coastal and estuarial areas are also suggested.