Cohen's method for preparing the nerve growth factor from mouse submaxillary glands was followed to the last ammonium sulfate fraction. Further purification was accomplished with carboxymethyl- and diethylaminoethyl- column chromatography. Three peaks were obtained for each column; the third peak obtained with diethylaminoethyl cellulose was the most active. Electrophoresis of this active fraction produced one anodal and two cathodal bands. Each band was inactive for nerve outgrowth. However combinations of the cathodal bands produced 3+ growth. One cathodal band was not dialyzable; the other was dialyzable and negative for ultraviolet absorption at 280 millimicrons.