Abstract: The filling of LNG and fuel oil into a powered ship is quite different. This paper describes a variety of powered ship gas filling methods, including LNG gas storage tank, shore base, ship base and floating chamber modes, analyzes the advantages and disadvantages of the different gas filling methods, and points out that better to adopt gas tank filling method because domestic LNG powered ships are absolutely inland ship. In the paper, the principle and adaptability of two boosting methods are comparatively analyzed. Self pressurization and pumping, and accordingly self pressurization is recommended for small storage tank and pumping method for super large tank. It is proposed to accomplish pipeline purge, inerting and pigging with nitrogen if there is residual liquid in gas ejecting pipeline, for LNG shall be kept from air. A profound research on gas filling technology of LNG powered ships is encouraged as a full new technical field.