Abstract: In this paper,two groups of experiments on multi-ribbed composite walls which include oblique section shear bearing capacity tests and normal section bending capacity tests are represented.Based on the results of the experiments,the composite wall's two typical failure modes and failure mechanisms are contrastively analyzed.The bearing capacity,deformation performance and other seismic performances of the walls with two different failure modes are studied.The results show that the wall with shear failure mode which is considered as an advantageous mode has several anti-seismic defending lines,for the three-part members of the load-bearing system(filler blocks,concrete frame grids and concealed frame) can play a key role gradually in three stages(elastic stage,elastic-plastic stage and failure stage).Contrastively,a reasonable failure mechanism is difficult to form in the wall with bending failure mode which is considered to be disadvantageous,for concrete crush or steel failure will be found at the feet of the end frame columns prior to the serious damage of the inner slab.As the ductility and deformability of wall occurring shear failure are absolutely superior to that of bending failure,a reasonable matching between the outer frame and the inner slab should be guaranteed.Finally,the formulas for normal section bending capacity of the wall are deduced,and the judgment criterion of large and small eccentric compression of the composite wall is established.