The spatial distribution of gas holdup in a stirred tank with a Rushton impeller and i.d. of 380 mm was measured by the fiber optic technique to show the different gas-liquid flow patterns including flooding. The data on loading/flooding transition are found consistent with the general correlation. The experiments were also simulated numerically by the Eulerian-Eulerian approach with the control volume formulation with the k-epsilon-A(p) two-phase turbulence model, and different flow patterns in the gas-liquid stirred tank were well demonstrated. It is found that the gas holdup in the impeller discharge stream is underpredicted, but in the broad bulk flow region the results of simulation are in good agreement with the experimental data.