The paper provided a very straightforward 3D CAD approach for the speedy evaluation of the seismic vulnerability of existing masonry pagodas. A 3D geometnc model of the structure and automatically calculates the collapse acceleration on a user defined failure mechanism can be applied in the approach. According to the previous numerical research in the field and post-earthquake surveys experience, five possible pagoda failure were provided and researchers also do the test for them. They are vertical splitting, simple overturning at the base, rocking with inclined yield lines and combined rocking and vertical splitting. The procedure is automatized and the direct application of the principle of virtual works -assuming that masonry behaves as ...