Abstract: In order to study on the out-plane seismic property of foam-in-place cavity walls, and seek the effective measures to improve the deformation capacity and overall performance of a cavity wall, 7 patches of foam-in-place cavity walls and 1 patch of a solid wall are built, and the model tests and numerical tests of out-plane seismic properties are carried out. The comparison indicates that the failure patterns, carrying capacity, deformation ability and coordination deformation ability of the numerical tests are agree with the data of model tests, and that the validity and accuracy of the model tests and numerical tests are both verified. The research shows that reinforced concrete transverse connecting beams play an important role in guaranteeing out-planes stability of the external wall. When wall cracks seriously, the steel ties coated plastic can play an important role in preventing the wall from collapse. The research results of deformation behavior show that foam-in-place cavity walls have the better ductility and energy dissipation and the internal as well as external wall of foam-in-place cavity wall have very well coordinating deformation capacity.