The conceptual design of subsea cryogenic transfer system of Liquefied Natural Gas (LNG) is proposed, and the LNG transfer system with removable cryogenic turret mooring pontoons for harsh environments is studied. The system design requirements include minimum water depth of 45 m, minimum Liquefied Natural Gas Carrier (LNGC) connection effective wave height of 4 m and minimum relief effective wave height of 8 m. The study results include concept designs for all system components, including removable cryogenic turret mooring pontoons, dynamic flexible cryogenic risers, subsea cryogenic sea pipes, cryogenic slip rings, subsea cryogenic valves and all related ship modifications. A feasible scheme is formed by the design for the LNG transfer system, which can be applied in practice, and is of good feasibility and economy for improving LNG transfer.