Based on a hydrodynamic two-fluid model [Brandani and Zhang, Powder Technol. 2006; 163(1-2): 80-87], the scaling relations developed by Glicksman et al., are modified to improve the understanding of the scale-up of jetting fluidized beds (JFBs). To estimate the ability of the proposed scaling rules to give similar results, simulations are conducted in CFX 4.4. We investigate in detail the effects of jet gas velocity on the scale-up rule. The similarities of jet evolutions and time-averaged radial viodage distributions are compared between large and small beds. The computational results confirm that the modified scaling rules are valid for JFBs when all dimensionless groups are matched between the prototype and large-scale beds.