Abstract: In this paper, for the 4-node isoparametric quadrilateral joint element with the same thickness, firstly the momentum equilibrium equation, the continuity equation for water and the energy balance equation are established. Secondly by using the Galerkin method all the governing equations are discretized in the space domain and in the time domain respectively, then a kind of joint element model for elastic analysis of coupled thermo-hydro-mechanical phenomenon in saturated discontinuities of rockmass is developed tentatively. Through the assumed computation examples for a stable percolation and a nuclear waste repository, it is shown that under the condition of existing discontinuities the displacements and the water heads at the two sides of the discontinuities are discontinuous, and the temperature is continuous but there are some differences compared with the case without discontinuity.