Gas entrainment and gas holdup characteristics have been studied in a modified downflow slurry liquid jet three-phase contactor. The effect of operating variables such as slurry liquid jet velocity, separator pressure, gas velocity and the concentration of solid on gas entrainment rate and gas holdup are investigated. Gas holdup data are analyzed by slip velocity model. Dimensionless correlations have also been developed to predict the gas entrainment rate and gas holdup by dimensional analysis. This study may be helpful for further understanding and developing the three-phase reactor for industrial application. (C) 2011 Elsevier B.V. All rights reserved.