The objective of this work was to investigate the main fludodynamic behavior of a constrained inverse fluidized bed in a draft tube airlift reactor (DT-ALR), with liquid in batch and air in continuous mode. The inverse fluidized bed was formed of relatively large particles (4.3-5.4 mm) that were composed of light polyethylene (PE), in the first case, and of particles (3.7-4.7 mm) that were composed of extremely light polystyrene (PS), in the second case. The influence of physical properties of liquid phase (surface tension and viscosity) on basic fluidodynamic characteristics was examined using the coalescence-inhibiting medium (1wt % aqueous solution of ethanol) and viscous medium (46 wt % aqueous solution Of Sucrose). It is shown that the overall gas holdup, induced liquid velocity, minimum fluidization velocity, and bed expansion are dependent on the superficial gas velocity and liquid and solid properties.