Tunnels that have recently been constructed are characterized by longer length than ever before and furthermore they frequently go through the ground area with poor conditions such as fractured zones. If ground strength is weak, plastic deformation of tunnel occurs, and occasionally a big fall may be brought about. Up to now, the construction work of tunneling has been executed as a sequential method placing the lining concrete after completion of excavation. Such a method requires a long time and much money to complete the tunnel. It is hard to ensure the stability of tunnel if tunnel is left undone for a long time after excavation in fracture zones or plastic grounds. For this reason, we tried to take simultaneous construction of tunnel excavation and lining concrete in order to not only shorten construction schedule but also stabilize the tunnel at the highly fractures zone as soon as possible. As preliminary consideration for simultaneous construction, in-situ tests are performed to calculate the isolation distance over which blasting vibration does not influence the strength of lining concrete. Improvement of ling form, placing method of concrete, ventilation using a dust collector, together with equipment arrangement, was made to assure the simultaneous construction work.