Potential future hydrogen market and possible applications of fusion were analyzed. Hydrogen is expected as a major energy and fuel mediun for the future, and various processes for hydrogen production can be considered as candidates for the use of fusion energy. In order to significantly contribute to reduction of CO2 emission, fusion must be deployed in developing countries, and must substitute fossil based energy with synthetic fuel such as hydrogen. Hydrogen production processes will have to evaluated and compared from the aspects of energy efficiency and CO2 emission. Fusion can provide high temperature heat that is suitable for vapor electrolysis, thermo-chemical water decomposition and steam reforming with biomass waste. That is a possible advantage of fusion over renewables and Light water power reactor. Despite of its technical difficulty, fusion is also expected to have less limitation for siting location in the developing countries. Under environmental constraints, fusion has a chance to be a major primary energy source, and production of hydrogen enhances its contribution, while in ''business as usual'', fusion will not be selected in the market. Thus if fusion is to be largely used in the future, meeting socio-economic requirements would be important.