Abstract: In this paper, a viscoplastic model has been adopted to carry out the finite element numerical simulation analysis of the time-dependent behaviours of soft-rock tunnel. The distribution of stresses andthe change of displacement of soft-rock tunnels are given with time and effects of support pressure,volumetric dilantancy of soft-rock and strength deteriorating on the stabilities of tunnels are discussedin details. Some useful conclusions and suggestions are provided for support designs of soft rock tunnels.