The present invention provides a plant cultivation method, which enables plant cultivation under high salinity environment for a long time. A method for hydroponic plant cultivation under high salinity environment, comprising a cultivation step of hydroponically growing a plant with a cultivation solution having a sodium chloride concentration of 1% by mass or more, during which a salt resistance imparting treatment is performed at least once by bringing a salt tolerance imparting agent into contact with at least a part of a root of the plant, thereby maintaining salt tolerance of the plant.
