Hydrogen is anticipated to be one of the promising energy carriers used in the 21st century. In Japan, research for establishing a hydrogen energy technology is being conducted in the WE-NET (World Energy Net-work) research program of the New Sunshine Project, promoted by the Ministry of Trade and Industry since 1993 and aimed at completion in 2020. At the first three years study of hydrogen tanker development, conceptual design of 200 000 m(3) hydrogen tanker based on the liquid natural gas ship technology and some investigations on the insulation and support system for hydrogen tank were carried out by the joint shipyard team in WE-NET program. A outline of our research and some considerations are reported.