Analysis of the liberation degrees of intracellular materials from Ehrlich ascites tumor cells by treatment of Triton X-100 was performed. The liberation process has two stages. In the first stage, cytoplasmic inorganic phosphorus were liberated at a concentration of about 0.01% of the detergent, and in the second stage macromolecules such as lysosomal enzymes were liberated at a concentration of about 0.03% of the detergent. Morphologically, the cells began to swell in the first stage but were not stained by Trypan blue, and the cells in the second stage became fully swollen and ruptured. The staining curve of the swollen and ruptured cells was closely in parallel with the liberation curves of the macromolecules.