Abstract: A framework structure comprises three or more primary constituent units each including two rigid diagonal members constituting the diagonals of a quadrangular lateral face of a solid and coupled together for relative rotation about a first rotation axis passing through the intersection of the diagonals. The primary constituent units are coupled to one another via second and third rotation axes into a ring-like form. A more complicated framework structure can be obtained by using a plurality of these framework structures as secondary constituent units which are coupled to one another with a coupler or a primary constituent unit used in common between adjacent ones of the secondary constituent units. The framework structure can provide one which is capable of being expanded and contracted in three-dimensional directions and which has rigidity in any directions.