Abstract: Observing the stress change of surrounding mass caused by excavating opening, the procedure to determine the load for simulating the movements of surrounding mass by Finite Element Method is discussed. Whilst load formula with effects of both the primary state of stress and the self-weight of surrounding rock mass is derived, the author points out that there is something wrong in the normal procedure in computing the excavation load by only considering the effect of primary state of stress. There are also sente calculation examples of practical engineering projects included, by which the necessity of using the procedure proposed In the paper in computing the excavation loads is then illustrated.