In order to evaluate the seismic performance of existing masonry buildings rapidly, a seismic evaluation method for masonry buildings was proposed based on the theory of seismic evaluation of existing buildings in Japan. By taking the lateral bearing strength of walls and tie columns of every floor of a masonry building as structural seismic capacity (SSC) index, the seismic performance was evaluated by comparing its SSC index and SSC requirement indexes. The SSC requirement indexes were obtained by analyzing the damaged multi-storey masonry buildings subjected to seismic intensities of 9 and 10 degrees in the Wenchuan earthquake. The results show that the proposed method can evaluate the seismic performance of multi-storey masonry buildings and assess the degree of earthquake damage.