Abstract: Ocean renewable energy is a carbon-free energy, including tidal energy, tidal current energy, wave energy, thermal gradient energy, salinity gradient energy and wind energy. With the rapid development of society, the demand for energy has been increasing and the development and utilization of marine energy has been paid more attention to around the world. The authors of this paper have introduced the development and utilization conditions, the existing problems and the prospects of marine energy in China. The development and utilization of marine energy is in conformance to the requirements of carbon neutral development and would play an important role in energy conversion, which is of great strategic significance to the coastal and island economic development, ecological environment protection and marine national defense construction.