The effect of the solid suspension to the gas hold-up in the bubble column was studied where by;
（1） The relation between the gas velocity (U_G) and the gas hold-up (1-ψ) in the independent bubble flow range (U_G≒0∼7 ㎝/sec) at different specific gravity of solid suspension and its weight was linear, while in the blow up flow range of bubbles the gas hold-up was constant to the gas velocity.
（2） In the independent bubbles flow range, the relation among the gas hold-up (1-ψ), the specific gravity (ρ) of solid suspension and its weight (W), the gas velocity (U_G) appeared as follows;