Abstract: Provided is a floating structure for solar power generating on water. The floating structure includes: unit lines including a main buoyancy body and an auxiliary buoyancy body arranged in a transverse direction and being arranged in a longitudinal direction; a connection member that connects the main buoyancy body to the auxiliary buoyancy body so that the bottom surface of the main buoyancy body is located lower than the bottom surface of the auxiliary buoyancy body; and a platform that connects auxiliary buoyancy bodies included in adjacent unit lines in the longitudinal direction. One or more ends of the main buoyancy body and the auxiliary buoyancy body include a first fastening portion and a second fastening portion that fastens two or more of the main buoyancy body and the auxiliary buoyancy body, and the connection member includes a support portion and third fastening portions provided at ends of the support portion.