Abstract: Composite Shear Wall (C-PSW) is one of the efficient systems against lateral loads. About 50 years ago, steel shear walls were used as a resistor against lateral loads, however, poor buckling of these walls made researchers use reinforced concrete layer in one or both sides of the steel shear wall in order to solve this problem which led to proposing composite shear wall. This study discusses the effect of rectangular opening positioning on seismic performance of the system. To do so, different models were analyzed under cyclic load using finite element method. The results showed that, the most appropriate position for creating an opening is bottom corners of the frame.