Bubble columns reactor is widely used as gas-liquid mixing and as reactors in many industries such as in chemical, petrochemical and biochemical. High interfacial area between the gas and liquid phase will enhanced an effective mixing, leading to improved heat and mass transfer characteristics under bubble columns become an attractive choice as reactors for the described processes. In this research, experimental work by using cylindrical acrylic bubble column with internal diameter of 0.15m and height of 1m was done. The bubble column is equipped by four nozzles with orifice diameter of 5 mm function as gas distributor attach at the bottom of the column. For this study, gas phase and liquid phase used are air and water respectively. The investigated variable parameter was mechanism of bubble formation, regime analysis and the relationship between superficial gas holdup and gas holdup. The techniques used in collecting data were visual observation, measurement technique and photographic method. The result showed that there were five stage of bubble formation based on experiment conducted. For gas holdup and superficial gas velocity relationship, it was discovered that the gas holdup increased with the increasing of superficial gas velocity. The relationship was proof to be in good agreement with published data proposed by previous researcher. .