Marine microorganism is the main driving force of the biogeochemical cycle of carbon, nitrogen, phosphorus and sulfur in the ocean, and plays an important role in global climate change. This research direction takes the marine microbial resources as the entry point, and systematically investigates the characteristics of marine microbes, such as the diversity and its systematic and evolutionary mechanism; physiological, genetic and biochemical mechanisms as well as the structural basis of extreme environmental adaptation;and the processes and molecular mechanisms of biogeochemical cycles of marine organic matter driven by these enzymes. In addition, the marine microbial enzyme engineering and its application are also emphasized in this direction .