Phospholipids combined with soluble proteins of the male Wistar Strain rats transplanted with Walker carcinoma were studied. The soluble fractions were extracted by 1) 1/15 M Phosphate Buffer (pH. 7.2), 2) 0.4 M NaCl from the nucleus and mitochondrial fractions of the liver, spleen and tumor of the rat. The phospholipids devided from soluble proteins were analysed and compared with those of normal rat by meaus of photodensitometrical technique and p(32) activity on thin layer chromatogram. 1. Total phospholipid per protein was decreased slightly in liver, increased in spleen of the tumorbearing rat. 2. Sphingomyelin was increased in liver, spleen and tumor tissue, lecithin in spleen and cephalin in tumor tissue were increased slightly. 3. In the tumorous condition, the L/C ratio in liver and spleen was higher than in normal, but in tumor tissue, it was lower than in normal liver or spleen.