Abstract: Oil and natural gas resources are important energy minerals and strategic resources. The ocean contains abundant oil and gas resources. Since its reconstruction in 1979, the Qingdao Institute of Marine Geology (the Qingdao Institute in short) has begun the investigation, research, and evaluation of marine oil and gas resources. Over the past 45 years, the Qingdao Institute has been continuing to carry out the studies in the correlation of oil and gas bearing basins in the sea area and adjacent areas, the investigation and evaluation of oil and gas resources in new area and new strata in the Yellow Sea and the East China Sea, the analysis of oil and gas exploration and development situation in China's sea area and the Sea Silk Road sea area, and the joint geological and scientific survey of key marine areas in the North Indian Ocean. This article reviews the 45-year history of oil and gas exploration and research in the sea area by the Qingdao Institute, summarizes the main achievement, and focuses on introducing the investigation techniques for oil and gas resources in the new areas and new strata, the new geological understanding of oil and gas in the new areas and new strata of the eastern sea area, the scientific research findings and understanding of the Indus Fan basin, the exploration and development situation, and strategic direction of oil and gas resources in the sea area; and puts forward the main challenges faced. At the same time, it looks forward to the main fields and directions of future oil and gas investigation, which is of great significance for further understanding of the wealth of oil and gas resources in the sea area, serving the management of oil and gas mining in the sea area, and ensuring national energy security.