Fluidized bed has many advantages such as high heat and mass transfer rates, temperature homogeneity and good mixing property. However, conventional fluidized bed has some limitations; operation at high gas velocity leads to slugging and there exists minimum particle size for the uniform fluidization. Recently, a rotating fluidized bed (RFB) has attracted special interest, since it can overcome the limitations. Due to the vessel rotation, the RFB can impart high centrifugal force to particles, leading to achieve uniform fluidization of even fine particles. The RFB also exhibits good particle mixing property with lower elutriation In this study, fundamental particle fluidization mechanism in RFB is analyzed by both experimental and numerical approaches. Handling and processing of fine particles is also discussed.