Pressure fluctuation characteristics at different axial and radial positions were investigated in a three-phase fluidized-bed Plexiglas column of 285 mm inside diameter and 4100 mm height operated with air, tap water and glass beads under different conditions. It was found that the whole column may display different flow regimes depending on the operating conditions, i.e. total homogeneous bubble regime, total transition regime, total turbulent bubble regime, while the two neighbouring or all three regimes may exist simultaneously at different heights of the column. Schemes of flow regime distribution, which changes with gas velocity, were given, and the criteria for flow regimes correlated with operating variables and axial distance above the gas distributor were established. It was also found that any flow regime was substantially identical at different radial positions across the column. Phase holdups at different heights of the column were measured by means of a combination of pressure drop and sampling methods. Correlations of gas and solid holdup in different flow regimes as a function of operating parameters and:axial distance from the distributor were established.