Abstract：When there is large number of samples of characteristic parameters，the Monte-Carlo method is a comparatively accurate method to compute reliability of structure. However，in underground engineering，available samples of those characteristic parameters are quite limited in quantity，so it is more practical to use response surface method instead. In the light of monolithic lining structure of railway tunnel，the results from response surface method are analyzed and compared with those from 100 000 samplings by Monte-Carlo method. It is found that the two methods are mutually in good agreement on all sections except the place where the bending moment is approximately zero，which shows that response surface method is feasible to calculate reliability of railway tunnel lining.
