The macromolecular components, constituting mitochondria, were analysed electrophoretically and turbidimetrically and following results were obtained.1. Macromolecules, extracted by acid or alkaline media, were analysed electrophoretically. It seemed probable that there should be little basic proteins which were in salt-like combination with other macromolecular.2. The macromolecules, which were extracted by alkaline, were complex with the isoelectric points about pH 4.5-5.0. It was supposed that the complex proteins constituting the Gel-phase of mitochondria were extracted in fhemselves, They are probably negatively charged within the cell, attracting a great deal of cations with them.3. The macromolecules, obtained by acid extraction, were relatively simple one. The protein part of the complex protein constituting the Gel-phase were profably extracted. The mechanisms of conbination of these proteins with nucleic acids and lipids were not so simple as the synthetic complex coacervate, and not only the ionic force but also the secondary force of binding (i. e. van der Waals force or hydrogen bond) or the specific steric configuration of macromolecules were probably contributing much to such combination. However, the analysis in detail were remained to be studied in future.