Professor Li’s research has focused on marine geology and geophysics, with particular emphasis on submarine exploration engineering, the tectonic evolution of marginal seas, and marine geothermal investigations. Through more than ten research voyages in the Okinawa Trough, he conducted marine geological and geophysical surveys of the Northwest Pacific marginal sea system and China’s adjacent waters, contributing to the understanding of the tectonic characteristics of the trench–island arc–back-arc basin system. In 1995, he proposed an East China Sea delimitation scheme based on the central rift axis of the Okinawa Trough, which provided scientific material for China’s subsequent submission to the United Nations. He also led the first seabed heat-flow measurements on the East China Sea continental shelf and participated in investigations that identified dense hydrothermal vents and submarine “black smokers” in the Okinawa Trough, contributing to the assessment of the region’s hydrothermal sulphide mineral resources. He has completed twelve large-scale marine survey research reports, authored or co-authored more than sixteen monographs, including Geology of the Northwest Pacific Marginal Seas, Geothermal Studies of the Okinawa Trough, and Geological and Geophysical Characteristics and Evolution of China’s Marginal Seas, and published more than seventy scientific papers and ninety strategic research articles. Through sustained research, leadership of national marine research programmes, and international scientific collaboration, Professor Li has contributed to connecting marine geological and geophysical research with applications in marine resource assessment, oceanographic exploration, and the scientific study of China’s marginal seas.