Based on Pushover method

three types of braced frames called K-shape eccentric braced frame（KEBF）

Y-shape eccentric braced frame（YEBF） and Y-shape knee braced frame（YKBF） are analyzed to find the influence regularities of the length and size of link beams on their earthquake-resistant performance（ERP）

then the three types of braced frames are compared in stiffness

ductility and energy dissipation.According to the analytical result

it can be found that under the reasonable design

YKBF can win the best stiffness and ductility

but KEBF can dissipate the most energy;the stiffness and energy dissipation of YEBF is the worst and its ductility is between the others.