A parametric analysis of constructional details for diagonal unbonded steel plate brace encased in reinforced concrete panel(Panel BRB) has been carried out to examine the effects of the width and yield strength of the brace,the brace thickness,the panel thickness,the width to thickness ratio of the steel plate brace,as well as the friction and clearance between the panel and the brace,on the working behavior of the diagonal Panel BRBs.When the appropriate clearance is provided,the regression formula to determine the smallest thickness ratio of panel to brace to prevent the panel from flexural cracking until 1/50 lateral drift is provided.The analysis reveals that,to prevent the brace from earlier local buckling,to reduce the number of buckling waves of the brace,and to decrease the frictional action and the punching shear force applied to the panel by the brace,an appropriate clearance and an appropriate ratio of width to thickness of the plate brace,which should not be larger than 5 but smaller than 19,should be adopted.