Particle clusters have a significant influence on the gas–solid flow behavior in circulating fluidized beds (CFB). To further investigate the parametric effects of fluidization state on the characteristics of clusters for Geldart group B particles, measurements of the transient solid concentration at different axial elevations and transverse positions were conducted in a 10.3-m high CFB test rig with quartz sand. Soong’s criterion and wavelet analysis were both used to specify the cluster identification threshold, and a following comparison of the two established thresholds showed that Soong’s criterion was a better choice for identifying clusters. By the selected threshold, the dynamic properties of clusters at different fluidization states were determined. The results revealed a weak dependence of the properties on the fluidization states. Lastly, based on the abundant experimental data provided, a modified cluster solid holdup model with higher prediction accuracy at εs < 0.01 was proposed.