Gas hold-up and liquid phase axial dispersion coefficient have been measured in a bubble column of 5.4 ㎝ diameter in which ionic solutions（in the range of concentration of 0.001 N to 0.1N） were employed in order to determine the effects of ionic strength on the objective parameters.
The gas velocity corresponding to minimum relative velocity is important in determining the ultimate bubbly flow fegime, which is transited to turbulent flow. This transition gas velocity, Vgt, is correlated with ionic strength of electrolytes.
Effects of gas velocity（1.3∼9.7 ㎝/sec）, liquid velocity(0.5∼2.1 ㎝/sec) and especially ionic strength on axial dispersion of liquid and gas phase hold-up are determined.
In the trubulent flow regime, the dispersion coefficient was found to be strongly affected by gas and liquid velocity, however, in the case of bubbly flow regime, the coefficient was not much affected by fluid velocities.