An original method of increasing seismic resistance in ancient stone domes is proposed. This structure consists of a thin reinforced concrete shell, provided with a support ring and cast above the existing stone dome. Results of nonlinear numerical analysis of stone dome taking into account non-elastic behavior of material are presented. These results are compared with corresponding results of linear analysis. The problem realized by an example of an actual conservation project in the seismic zone of Georgia. The series of structural analyses were performed using the finite-element method. The obtained results show the importance of considering the non-linear characteristics of material.