Pressure drops were measured for air-water system in a cocurrent, upflow bubble column containing each of four types of packing : Raschig rings, Intalox saddle, open-end screen cylinder and solid cylinder. The ranges of variables studied vary from 0 to 0.09 m/s for gas flow rate, 0 to 0.094 m/s for liquid Bow rate and 0.475 to 0.976 for bed porosity. The experimental data well support a single-parameter model developed on the basis of the separated flow concept of Murdock (1962) and Lin (1982).