Earthquake force reduction factor is the integrative parameter involving policy

technology and economy.In this paper

taking RC frame structures as an example

the method of determining earthquake force reduction factor for RC frame structures is introduced.The shortcomings of Chinese seismic design code for using design earthquake force-ductility grade are pointed out

on the basis of which the basic characteristics of the three components of earthquake force reduction factor are illustrated.The method of determining the earthquake force reduction factor is described in four steps.The proposed method provides a useful reference for determining reasonable values of earthquake force reduction factor in seismic design of buildings.