In a compression test in a cylinder for kneaded wet powder, the relation between the arbitrary level y in the compressed material and pressure p exerted at y was clarified analytically by introduction of a compression factor in. A clear relation between m and the kneading result of the test material was also recognized, By analyzing the relation between m and the frictional resistance between the material and the inside wall of cylinder, the resistance was shewn theoretically to increase with kneading time, and m was thus shown to be an index of the kneading result of the material.