Provided is a technology that facilitates a calibrating operation. A ship steering system for outdrive device includes an outdrive device, a control device that provides an instruction about a turning direction of the outdrive device, and a ship steering lever that instructs the control device about a traveling direction of a hull, and is provided with a monitor capable of displaying an image for matching an actual traveling direction with the traveling direction of the hull according to the instruction from the ship steering lever. The monitor shows the direction in which the ship steering lever is tipped, and indicates that the operation is proper if the direction in which the ship steering lever is tipped corresponds to a pre-set direction.