The correlation between dissolved cadmium (Cd) and phosphate (PO₄) in the ocean is often used to reconstruct paleoproductivity. Based on the intermediate data product IDP2021v2 released by GEOTRACES (an international study of the marine biogeochemical cycles of trace elements and isotopes) in 2023 and related literature published in the past 40 years, this paper reviews the latest research progress regarding the correlation between Cd and PO₄ in the ocean. It summarizes the Cd-PO₄ relationship in various ocean basins and identifies their major influencing factors. The controlling factors affecting the oceanic Cd-PO₄ relationship differ from surface to deep water and generally exhibit a bilinear correlation. In this study, the key processes controlling the correlation in different water layers are summarized, including the absorption of phytoplankton in the upper water (<200 m), remineralization of particulate Cd and P, mixing of water masses in the intermediate water mass (500~1 000 m), and mixing of different water masses in deep water (>1 500 m). The northward migration of Antarctic intermediate and bottom water from the Southern Ocean is vital in shaping the global ocean Cd-PO₄ relationship.