To study the vibration control effect of the mega structure with buckling restraining brace（BRB）

a 48-story mega frame structure was designed with SAP2000

under the requirements for Intensity 8fortification against earthquakes.And then

all the braces of the mega structure were replaced by BRBs whose stiffness are equal to common braces or BRBs whose area are equal to common braces

respectively.The two updated structures are referred to as the EKBRB structure or EABRB structure.Finally

elastoplastic time history analysis of the three structures were conducted under Intensities 8

8.5and 9earthquake.The results show that interstory drift ratio of BRB structure is significantly reduced and changes more uniformly under Intensity 8earthquake compared to the mega structure;the BRB structure meets the seismic fortification target that repairable under severe earthquake and no-collapse under super-strong earthquake.Thus it can be seen that the BRB structure provides enough emergency capacity for structures.