The typical failure of moment frames with dropped stories is caused by the failure of upper ground story columns.Four model frames were designed and numerically analyzed to evaluate their seismic performance and improvement effect.Research results indicate that the seismic collapse-resistant capacity of frame with dropped stories is weaker than that of general structure.The ductility of upper ground story columns is high for moment frames with dropped stories

which would be destroyed under rare earthquake;the addition of tensile beam has certain influence on the failure mode of moment frames with dropped stories

but not significant.The seismic collapse-resistant capacity of frame with dropped stories can not be improved by the addition of tensile beam.The effect of the failure mode and the seismic collapse-resistant capacity of moment frames with dropped stories and the improved measure are remarkable.This is closer to the common structure.