The general purpose of the experimental investigations described here has to study the hydrodynamic properties of gas-liquid fluidized beds. Gas –liquid fluidization of or three-phase fluidization is a chemical engineering operation where all the three phases are brought into contact with each other. This contact is brought about by passing the gas and liquid trough the bed of solids. The solids are said to be in a fluidized state when they are suspended in the continuous phase.Hydrodynamic properties such as gas hold-up, liquid hold-up and bed porosity have been studied. These properties depend upon certain independent variables such as gas flow rates, liquid flow rate, particle size, static bed heights, gas density, liquid density, solid density, liquid surface tension, liquid viscosity, gas viscosity and particle shape. During the course of this experimental investigation only four of these parameters have been varied, viz, gas flow rates, liquid flow rates, static bed height and particle size.The result of these experimental investigations is discussed and correlations have also been developed for the hydrodynamics properties studied.