Abstract: Due to the increasing impact of human activities in recent decades, the nearshore marine environment has undergone significant changes compared to the past. Scientific understanding of the characteristics, changes, and control factors of the nearshore marine environment is of great significance for addressing global changes and has become an important topic of current oceanographic concern. As one of important marginal seas of China, the East China Sea has a unique circulation system and gives birth to three typical ecosystems linked to the Yangtze River Estuary, the Upwelling Current, and the Kuroshio Current, respectively. Its marine scientific research is critically important to China's marine resource development, environmental protection, and national security. This article reviews the progress of marine research in the East China Sea with major focus on marine biogeochemistry. It summaries relevant research progress in physical oceanography, marine chemistry, marine geology, and biological oceanography, and explores existing problems and looks forward to future development directions. Existing studies show that the marine environment in the East China Sea is deeply influenced by human activities and climate change, and exhibits a new pattern. The discharge of the Changjiang River and the Kuroshio as well as its intrusion into the continental shelf region are main driving forces for formation of the three ecological systems in the East China Sea. In addition to main circulation system, the penetrating front and cross-shelf current are main dynamic processes connecting the water between the inner and outer shelves in the East China Sea, which promots cross-shelf transport of important biogenic materials such as carbon. Although related research has achieved certain progress in areas of marine ecological environment, climate change, and marine disasters, we are still facing many challenges due to insufficient data and limited studies. Considering the significant temporal and spatial variations of marine environment and the major environmental concerns of eutrophication and estuarine hypoxia, it is necessary to strengthen the regional oceanographic research on the East China Sea. In the future, we should encourage free exploration and research, strengthen international cooperation, enhance data sharing and technological innovation capabilities, and promote marine research in the East China Sea to an academic higher level.