Most equivalent damping ratio (EDR) models available to date for RC framed system are generally difficult to describe the structural hysteretic characteristic effectively since they are derived on the bases of equivalent single degree of freedom system. In this paper, 66 RC framed structures with various parameters and configurations are established based on the current seismic design code and monotonic pushover analyses are implemented. Then, 51 structures that have ductility deformation mechanism are selected to perform cyclic pushover analyses for establishing a global EDR model based on the principle of equating energy dissipation. Considering that this EDR model may underestimate the displacements demand, nonlinear dynamic analyses (NDA) are implemented and this EDR model is modified. It is found that the results obtained by nonlinear static analysis using the proposed modified EDR are consistent with those obtained by NDA. The proposed EDR model is of wide applicability and can reflect the global energy dissipation characteristics of RC framed structures.