[Problem to be solved] An object of the present invention is to provide a zero emission power generation sailing ship, wherein generated electric power is consumed for electric demand in the ship or consumed for electric demand in the ship and for driving the ship in response to wind condition, thereby realizing zero emission navigation.[Means for solving the problem] A zero emission power generation sailing ship comprises 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 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 further comprises a course selecting device provided with a computer program for selecting course based on ocean wind forecasting data so as to prevent exhaustion of the electric power stored in the energy storage device.