Dynamic properties of particle distribution behaviors in the circulating fluidized bed with rolling motion have been clarified by both Electrical Capacitance Tomography (ECT) experiment and CFD-DEM simulation. In the present study, the amplitude and period of the rolling motion were maintained at Theta = +/-pi/12 rad (+/- 15 degrees) and T = 5 s, respectively. Limestone particles (Geldart group B) were used as the circulating particles. As a result, the rolling motion causes little impact to the flow directional profiles of particle volume fraction due to the negligible inertial forces and changes of gravity component. However, both the experimental and simulation results indicate that the rolling motion has a dominant influence on the particle distribution un-uniformity in the radial direction. An obvious periodical variation of the particle volume fraction appears under the rolling motion due to the significant effect of the resultant force of the gravity component and inertial forces in radial direction, whereas this phenomenon did not appear under the upright condition in any previous studies. (C) 2014 Elsevier B.V. All rights reserved.