The objective of the study is to investigate the influence of seismic analysis of tunnel systems (single and twin tunnels). The seismic analysis is significant for tunnel projects in urban cities to avoid the collapse of tunnels in this crowded city due to displacements generated as a result of earthquake waves. A case study is The Greater Cairo metro line No.4, Phase No.1. To evaluate the influence of seismic waves on single and twin tunnels, four cases were simulated, the first case of a single tunnel and three cases of twin tunnels. For more serious understanding of the issue of seismic waves on twin tunnels, the horizontal, vertical and diagonal alignment are analyzed.. Total displacement was presented for tunnel systems. Moreover, induced internal forces in tunnel lining have been computed. The paper presents a two-dimensional model using numerical simulations by PLAXIS program. Based on the calculated result, a higher displacement occurs in tunnel lining during the earthquake. The maximum change of internal forces during an earthquake occurs in shear force, then bending moment. Moreover, the normal force of tunnel lining is less affected by seismic actions.