Abstract：Meso-scale flow structures were investigated in a cold mode bubbling and turbulent gas-solid fluidized bed. Solid holdup transient signals were measured in different axial and radial positions, and a Matlab program was compiled to decouple the transient signals. The third moment (skewness) analysis method was employed to identify the threshold value of the bubble phase which varied in a range of 0.26-0.35 in the center of the fluidized bed. As superficial gas velocity increases, the mean solid holdups of both bubble phase and emulsion phase decrease. The mean solid holdup of agglomerates ranges from 0.55 to 0.555, and it almost does not change with superficial gas velocity and radial position. The appearance frequency of particle agglomerates varies from 0.5 Hz to 3.2 Hz.