A wave force generation system comprising: a power conversion portion comprising a hydraulic cylinder configured to generate a hydraulic pressure by a six degrees-of-freedom motion of a movable object floating on waves, wherein when a force is applied to the hydraulic cylinder in one direction thereof, the power conversion portion allows a fluid to flow along a first path, to produce electric energy, and wherein when a force is applied to the hydraulic cylinder in another direction thereof, the power conversion portion allows the fluid to flow through a second path that allows the fluid to bypass and flow in a direction opposite to the first path, and the second path is merged with the first path, to produce electric energy, whereby the system further comprises a motion transmission portion and the motion transmission portion includes a plurality of tensile force transmission members connected to at least three portions of the movable object, characterized in that each of the tensile force transmission members comprises a first driving portion configured to drive the hydraulic cylinder, and a restoring force transmission portion, wherein when a tensile force is applied to the tensile force transmission members, a force is applied to the first driving portion and to the hydraulic cylinder in the one direction, and when the tensile force is released in each of the tensile force transmission members, the restoring force transmission portion applies a force to the hydraulic cylinder in the other direction, wherein the first driving portion converts movement of each of the tensile force transmission members into a reciprocating rectilinear motion and transmits a force to the hydraulic cylinder. a power conversion portion comprising a hydraulic cylinder configured to generate a hydraulic pressure by a six degrees-of-freedom motion of a movable object floating on waves, wherein when a force is applied to the hydraulic cylinder in one direction thereof, the power conversion portion allows a fluid to flow along a first path, to produce electric energy, and wherein when a force is applied to the hydraulic cylinder in another direction thereof, the power conversion portion allows the fluid to flow through a second path that allows the fluid to bypass and flow in a direction opposite to the first path, and the second path is merged with the first path, to produce electric energy, whereby the system further comprises a motion transmission portion and the motion transmission portion includes a plurality of tensile force transmission members connected to at least three portions of the movable object, characterized in that each of the tensile force transmission members comprises a first driving portion configured to drive the hydraulic cylinder, and a restoring force transmission portion, wherein when a tensile force is applied to the tensile force transmission members, a force is applied to the first driving portion and to the hydraulic cylinder in the one direction, and when the tensile force is released in each of the tensile force transmission members, the restoring force transmission portion applies a force to the hydraulic cylinder in the other direction, wherein the first driving portion converts movement of each of the tensile force transmission members into a reciprocating rectilinear motion and transmits a force to the hydraulic cylinder.