In recent years, the oceans have provided an important source of highly promising new anti-tumordrugs for innovation and screening, with approximately 56% of biologically active compounds being discovered to have anti-tumor effects each year. In this study, we classified and summarized the approved drugs of marine origin in terms of anti-tumortherapy, and firstly, we briefly overviewed the role of the immune system in cancer pathogenesis and discussed the current dilemma of cancerimmunotherapy and highlighted the main anti-tumor targets of marine drugs. Further, with a focus on tumorimmunity, we classified and outlined the history of currently approved marine original drugs by species origin, structural features, relevant pathways, and clinical application and therapy. Lastly, the limitations of current marine drugresearch were discussed, as well as prospects and trends in new drug development.