A zero emission power generation sailing ship comprising: a sail provided on a deck, a water turbine-propeller, a power generator-motor which is driven by the water turbine-propeller operating as a water turbine and drives the water turbine-propeller operating as a propeller, and an energy storage device (7a, 7b) for directly storing electric energy generated by the power generator-motor or converting the electric energy into energy of a substance and storing the substance, wherein the water turbine-propeller operates as a water turbine and the power generator-motor operates as a power generator so as to generate electric power and a part of the generated electric power is consumed for electric demand in the ship and residual part of the generated electric power is stored in the energy storage device when the wind is strong, while the power generator-motor operates as a motor and the water turbine-propeller operates as a propeller and a part of the electric power drawn from the energy storage device is consumed for electric demand in the ship and residual part of the electric power is consumed for driving the power generator-motor operating as a motor when the wind is light, and characterized in that the zero emission power generation sailing ship further comprises a course selecting device provided with a computer program configured to select course based on ocean wind forecasting data so as to prevent exhaustion of the electric power stored in the energy storage device (7a, 7b), a water electrolyzing device driven by the electric power generated by the power generator-motor, a hydrogenated aromatic compound generator for reacting aromatic compound with hydrogen generated by the water electrolyzing device so as to generate hydrogenated aromatic compound, an aromatic compound storage tank, a hydrogenated aromatic compound storage tank, a hydrogen separator for separating hydrogenated aromatic compound into hydrogen and aromatic compound, and a hydrogen fueled power generator. a sail provided on a deck, a water turbine-propeller, a power generator-motor which is driven by the water turbine-propeller operating as a water turbine and drives the water turbine-propeller operating as a propeller, and an energy storage device (7a, 7b) for directly storing electric energy generated by the power generator-motor or converting the electric energy into energy of a substance and storing the substance, wherein the water turbine-propeller operates as a water turbine and the power generator-motor operates as a power generator so as to generate electric power and a part of the generated electric power is consumed for electric demand in the ship and residual part of the generated electric power is stored in the energy storage device when the wind is strong, while the power generator-motor operates as a motor and the water turbine-propeller operates as a propeller and a part of the electric power drawn from the energy storage device is consumed for electric demand in the ship and residual part of the electric power is consumed for driving the power generator-motor operating as a motor when the wind is light, and characterized in that the zero emission power generation sailing ship further comprises a course selecting device provided with a computer program configured to select course based on ocean wind forecasting data so as to prevent exhaustion of the electric power stored in the energy storage device (7a, 7b), a water electrolyzing device driven by the electric power generated by the power generator-motor, a hydrogenated aromatic compound generator for reacting aromatic compound with hydrogen generated by the water electrolyzing device so as to generate hydrogenated aromatic compound, an aromatic compound storage tank, a hydrogenated aromatic compound storage tank, a hydrogen separator for separating hydrogenated aromatic compound into hydrogen and aromatic compound, and a hydrogen fueled power generator.