Expression-deliquoring tests using three types of paper sludges (tissue, newsprint, and paperboard) as deliquoring agent were carried out in order to investigate the effects of sludge dosage and pressure on the expression-deliquoring of slurry. In case of the tissue sludge, the highest compression rate was achieved when 5% of deliquoring agent was added, while in cases of the newsprint and the paperboard sludge, 7%. Compression rate was increased as pressure increases. Porosity was dcreased as pressure increases. The lowest porosity was observed when 5% of tissue sludge was added.