Local bubble characteristics in different flow regimes of three-phase fluidized beds were investigated by means of an electro-conductivity probe. Bubble size, bubble rising velocity, bubble frequency and gas holdup were correlated with the operating parameters, axial and radial positions of the column in different flow regimes. Based on the measured results and the analyses of the forces acting on each phase, a one-dimensional three-phase hydrodynamic model was developed. With the radial distribution of liquid turbulent kinematic viscosity, the hydrodynamic model was solved for different flow regimes with parameters accordingly. The results show that the calculations correspond well to the measured results of local gas and liquid velocities.