Abstract: Floating Liquefied Natural Gas System (FLNG) is a new type of natural gas development platform, and its theoretical research is now one of the focuses in the field of ocean engineering. In this paper, the basic components of a FLNG unit were introduced and several hydrodynamic responses which occur easily during its operation in sea areas were mainly illustrated, including coupling hydrodynamics among multiple floaters (FLNG and LNG cargo ships), effects of tank sloshing on the FLNG, coupling hydrodynamics between FLNG and the mooring system, and horizontal plane stability of single-point mooring FLNG system. Then, domestic and foreign research achievements on the FLNG technologies were reviewed. It was proposed to install the dynamic positioning system on the FLNG and to use the research method which combines the model with numerical simulation. The research results provide the theoretical references and technical support for further FLNG research.