After the Wenchuan earthquake, a large number of infilled frame structure of underlying weak layer (the bottom of non-filled walls, the upper wall of clouds filling) of the housing system did not appear "weak beam strong column" of the failure mode. Established pure frame structure of finite element model which considered the quality of in filled wall without taking into account of its stiffness and strength and the frame of finite element model which contains filler wall, and carried out elastic-plastic time-history analysis with established finite element model of two under earthquake, through analysis and comparison understand reasons which infilled frame structure of underlying weak layer did not achieve the "weak beam strong column" ductile failure mechanism, and further explored how to achieve "weak beam strong column" failure mechanism for infilled frame structure of underlying weak layer, raised a number of assurance measures.