1) I have succeeded in the extraction of bone marrow polysaccharides out of red bone marrow of a calf due to method in which first of all I make them issue out into the water after it have been heated into the distillated water, remove the protein content owing to CuSo(4) and NaoH; then, removing the salt by ion-exchange resin, cause it to precipitate due to alcohol and ether. 2) This substance is exhibited as white powder with non-crystal nature, which sustains a slight degree of wet-absorbing property, and able to dissolve easy in water, but is indisoluble toward ether, alcohol and aceton. Also, it invariably has proved to be (+) in Molisch reaction, but to be (-) in any these reactionse of Biurt, Sulfosalicyl acid, Xanthoprotein and Ninhydrin. Furthermore, by hydrolysis, it has reduced to Fehling solution and after analysis of element I cannot detect any nitrogen. 3) In case a proper amount of this aubstance (per Kg 1mg) be injected into ear veins of a normal rabbit, an increase of erythrocytes has been detected for a few hours after the injection. This function has proved rather tough toward alkali or heat, but is lost by being heated due to acid. 4) I could detect Galactose, Rhamnose, Glucuronic acid and Galacturonic acid for its constituent sugars, owing to paper chromatography.