Lipids combined with soluble proteins in nucleus and mitochondrial fractions of the liver, spleen and tumor of rats bearing Walker carcinoma were compared with those of normal rats by analysis on thin layer chromatography. The tumor used in the experiment was about one per cent of the body weight. 1) The extracting solutions used in the experiment, 1/15M phosphate buffer, 0.4M NaCl were better than 0.1M acetate buffer and 0.1N NaOH. 2) Proteins per wet tissue weight were increased slightly both in liver and spleen. Tumor had more protein than that of the normal liver. 3) Total lipids per protein were increased slightly in the spleen but decreased in the liver, those of the tumor were higher than that of the normal liver. Triglyceride probably had important role on the results.