The hydrodynamic behavior of a circulating powder-particle fluidized bed (CPPFB) was examined in terms of total solid entrainment rate and fine particle hold-up. Experiments were carried out in a circulating fluidized bed of 2 m in height and 0.052 m in diameter, using FCC catalyst particles of 66 mum as the coarse particles and cohesive aluminum hydroxide powders of 0.5 mum, 1 mum and 3 mum as the fine particles. The effects of adding cohesive fine particles on the total solid entrainment rate were investigated under different operating gas velocities. The total solid entrainment rate at the same operating gas velocity was found to increase with the increase in the fine particle size and decrease with the increase in fine particle hold-up.