Gas-solid fluidized beds are widely used in many industrial operations. The study of flow hydrodynamics is very essential while designing a gas-solid fluidized bed reactor. In densely packed beds, interphase momentum transfer coefficient plays a vital role in characterizing the fluidized bed dynamic behaviour. In gas-solid flows, drag force is critical to model the interphase momentum transfer. The motivation of this paper is to study the effect of drag on the flow properties of bubbling and turbulent fluidized beds using Computational Fluid Dynamics (CFD). Eulerian two fluid model using Kinetic Theory of Granular Flow (KTGF) options coupled with suitable drag models such as Gidaspow, Syamlal O'Brien, Beetstra, Brucato, Simon, EMMS and Tenneti drag correlations are employed for this purpose. CFD predicted results are validated against experiments in terms of bubble diameter, axial, radial variation of solids volume fraction and bed expansion ratio. In case of bubbling fluidization with central gas jet; Brucato, Beetstra and Simon drag models are closely predicted the experimental solids volume fraction and bubble diameter. For turbulent fluidization; Brucato and EMMS drag models are predicting close void fraction values against experimental measurements. Critical assessment of suitable drag model has been made in detailed manner.