The hydrodynamics of a 10-cm-diameter cylindrical bubble column at the superficial gas velocity of 2, 4, and 8 cm/s are investigated by computer-automated radioactive particle tracking (CARPT), particle image velocimetry (PIV), and computed tomography (CT). These experimental techniques are capable of providing the knowledge of velocity and holdup fields in a bubble column system, which are essential as the experimental benchmark for modeling of such systems. The flow field of liquid phase, as well as the Reynolds stresses, obtained by CARPT and PIV in an air-water system are compared in detail. The results indicate that CARPT and PIV complement each other well. Further, the profile of gas holdup obtained by gamma ray based on CT compares favorably to the independently determined holdup.