A frame structure comprising a plurality of PC (precast) columns arranged in a first direction (X) and a second direction (Y) crossing the first direction in plan view, at least one first PC beam incorporated with first main beam rebars including an upper rebar and a lower rebar each extending in a longitudinal direction of the at least one first PC beam, each first PC beam being supported by a pair of the PC columns adjoining each other in the first direction, and at least one second PC beam incorporated with second main beam rebars including an upper rebar and a lower rebar each extending in a longitudinal direction of the at least one second PC beam, each second PC beam being supported by a pair of the PC columns adjoining each other in the second direction; wherein each first PC beam is formed with first blind holes opening out from each longitudinal end surface thereof so as to each form a first joint for a corresponding end of the corresponding first main beam rebar , and each of the adjoining PC columns is formed with first through holes opening out opposite to the first blind holes ; and wherein each longitudinal end of the first PC beam is rigidly connected to the corresponding PC column by a first rebar inserted in each first blind hole and the corresponding first through hole, the first rebar being connected to the corresponding first main beam rebar via the first joint , and a gap defined around the first rebar in the first through hole being filled with grout; characterised in that : each second PC beam is formed with second blind holes opening out from each longitudinal end surface thereof so as to each form a second joint for a corresponding end of the corresponding second main beam rebar , and each of the adjoining PC columns is formed with second through holes opening out opposite to the respective second blind holes ; each longitudinal end of the second PC beam is rigidly connected to the corresponding PC column by a second rebar inserted in each second blind hole and the corresponding second through hole , the second rebar being connected to the corresponding second main beam rebar via the second joint , and a gap defined around the second rebar in the second through hole being filled with grout; each first rebar has one end received in the corresponding first blind hole and another end received in the corresponding first through hole , and each second rebar has one end received in the corresponding second blind hole and another end received in the corresponding second through hole , and the first PC beams are rigidly connected to the associated PC columns at a different height from the second PC beams . each second PC beam is formed with second blind holes opening out from each longitudinal end surface thereof so as to each form a second joint for a corresponding end of the corresponding second main beam rebar , and each of the adjoining PC columns is formed with second through holes opening out opposite to the respective second blind holes ; each longitudinal end of the second PC beam is rigidly connected to the corresponding PC column by a second rebar inserted in each second blind hole and the corresponding second through hole , the second rebar being connected to the corresponding second main beam rebar via the second joint , and a gap defined around the second rebar in the second through hole being filled with grout; each first rebar has one end received in the corresponding first blind hole and another end received in the corresponding first through hole , and each second rebar has one end received in the corresponding second blind hole and another end received in the corresponding second through hole , and the first PC beams are rigidly connected to the associated PC columns at a different height from the second PC beams . <EOS>