This newly developed segment for tunnel lining is composite structure type combining a box-shaped ductile cast iron shell frame and reinforced concrete. We call this new type segment Ductile and Reinforced Concrete Segment ''DRC''. Thanks to the higher strength and the higher rigidity of this DRC Segment comparing to the conventional RC Segment, the great reduction of the segment thickness can be achieved, which enables the excavating cross-section area smaller by 7-10%. While developing DRC segments, we had some kind of performance tests, using full size test pieces. These tests were conducted to verify basic performance and to prove DRC segment being composite structure. Jointing structure of the segment is not bolt-jointing, but wedge application type, which can make the time of erecting the segments shorter only by pushing in the segments to the axial direction of tunnel with the shield jack. In addition, because of no bolt box, the inside surface is completely smooth and flat and no secondary lining is required. Thus, DRC segment is suitable for water channel tunnel, which is subject to internal water pressure and for highway and railway tunnel of large diameter. DRC segments were adopted as two tunneling projects. The first one was discharge channel tunnel and the other was highway tunnel. The discharge channel tunnel has 11.8 m outside diameter and the length is 1235 m. The construction of this tunnel was completed on May 29th 2002. In this tunnel construction, we have got the excellent performance results such as the time saving of erecting the segments, about half of that when the segments are erected by the bolt jointing, the achievement of almost complete roundness of the internal tunnel surface, no water leakage, etc. Through the above project, we have proved that DRC segment has the great advantages in terms of the productivity of erection, quality of tunnel and economy. The highway tunnel has 12.83 m outside diameter and the length adopted DRC segment is 132 m. The erection will start in 2003. (A). Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.