The interaction of frames with brick masonry buildings in the story-adding structures of existing brick masonry buildings by incorporated masonry-in-frame system is ambiguous as well as the analytical model.It is proposed that the seismic strengthening effect of the new frame structure on the existing brick masonry may be considered to be similar to that of constructional columns and beams,based on a number of relevant test data from abroad and home.Furthermore,the most disadvantaged internal force stage of the frame and brick masonry structure is analyzed,respectively,which is expected to be served as the basis of governing structural design.