Eccentrically braced frames (EBFs) are commonly used as lateral load resisting systems for steel structures. When subjected to strong seismic excitations, it is expected that the lateral load resisting system will experience inelastic deformations. Most design codes list strength reduction factor values corresponding to each structural system as a parameter to consider the ability and the efficiency of such system to dissipate earthquake energy through inelastic deformation. Hence, earthquake loads are reduced to match the actual behavior of structures under seismic loads. This is performed by dividing the calculated base shear by strength reduction factor. Strength reduction factor consists of three main components representing ductility, over-strength and redundancy of the considered structure. These factors depend mainly on properties of the structural system and construction material. In this research, a parametric study is conducted to calculate the strength reduction factor values for eccentrically braced steel frames. The considered parameters include storey height, number of bays, and shear link length in addition to location of braced bay. Nonlinear static (pushover) and time history analyses were performed in order to calculate reduction factor for different 2-D models. Effects of different considered parameters on strength reduction factor were evaluated and compared to the values proposed by different design codes.