Publication of this review will occur within a few months of the tenth anniversary of the volume, Concepts in Marine Organic Chemistry (Anderson, 1977). That volume reviewed the topic up to that time and provided a prognosis and stimulus for a strong program of research in marine organic geochemistry for the past ten years. The previous United States report to IUGG on this topic (Gagosian, 1983) provided an excellent review of the literature of 1979–1982 and focused in an informative manner on several specific subtopics. This review adopts the same organization format, although some of the subtopics are new and some previous subtopics are not emphasized because of the marine organic geochemical research and the new divisions within the United States report on Chemical Oceanography and Paleooceanography.