This work numerically conducted a comprehensive study on the jet effect of inlet distributor arrangements on the flow structure of gas solids two-phase flow in circulating fluidized-bed risers. A computational fluid dynamics (CFD) model based on the Eulerian-Eulerian approach coupled with granular kinetics theory was adopted to carry out the simulation Simulation results were compared with the experimental data. It was found that the inlet distributor has a great effect on the entire flow structure. The numerical results using jet inlet approaches predicted more distinct core-annulus flow structures mimicking the experimental results while the uniform inlet condition predicted a very flat flow structure. The jet effect of the inlet distributor is clearly revealed. A Imp lateral flow can be seen because of the jet effect A reasonable CFD model needs to take into account the inlet distiibutor configuration and consider the jet effect at the inlet.