The ideal failure mode of reinforced concrete frame - shear wall structure is from coupling beams to the bottom of shear wall, then from frame beams to frame columns. Structures which composed by four shear walls and M specimens of the framework with 12, 14,16,18,20 layers are used as "N-storey and 4-shear walls and M- framework" example model. Then structures were designed and analyzed by elastic-plastic dynamic time history analysis method by using the SNAP software. With the increase of M, the changes of structures’ failure mode were investigated. Based on the distribution of cumulative hysteretic energy (EH), the relationship between the stiffness characteristic value and best failure mode was analyzed and determined, and the critical stiffness characteristic values which meet the ideal failure mode requires were proposed, then calculated the relative shear wall stiffness according to the critical stiffness characteristic. The analysis of "N-storey and 4-shear walls and M- framework" which with critical stiffness characteristic shows that the wall length of a unit area, the area ratio, the period, the inter-story displacement angle, the force and deformation characteristics are meet the requirements of "Technical specification for concrete structures of tall building" and empirical formula etc, therefore, the method of study is correct and the research results is reasonable.