The influence of impellers system and type of liquid on the gas hold-up in the vessel has been presented in this paper. The analysis of gas hold-up was conducted on the basis of the data obtained in the vessel of the diameter D = 0.288 m, where the vessel was filled by a liquid up to the height H = 2D. The vessel was equipped in 24 vertical tubular baffles located on the circuit and two high-speed impellers situated on a shaft. Five different configurations of high-speed impellers were employed. The experiments in the gas-liquid system were conducted for setups which differed in capability of gas bubbles coalescence. The results of the experiment of the gas holdup for the five impellers configurations and four gas-liquid systems were presented in the graphic form and they were described mathematically.