Three kinds of functional regions such as continuous slurry(εf), bubble(εb) and wake(εw) regions were identified, and the individual phase holdups of each functional region were determined in a three-phase slurry bubble column of 0.152 m ID. The holdups of bubble and wake were measured by adopting the electrical resistivity probe method. Effects of gas velocity and solid concentration in the slurry phase on the individual holdups of functional regions in the column were discussed. The holdup of continuous slurry phase decreased but that of bubble or wake increased, with an increase in the gas velocity in the column. The increase of solid content in the slurry phase could lead to the increase in the holdup of continuous slurry phase but decrease in the bubble or wake holdup. The portion of wake holdup was in the range of 15~40% of the bubble holdup, which decreased with increasing gas velocity or solid content in the slurry phase. The individual holdups of three functional regions were well correlated with operating variables within this experimental conditions.