Whole starch, an~ylose, amylopectin, and glycogen (polymeric carbohydrates of the a-D-glycosidic linkage type) were nitrated by nitric acid in the presence of phosphoric anhydride and stability properties of the nitrated products were studied. Crude amylose nitrate is more stable than a~nylopectin nitrate and the latter is less stable than the whole-starch nitrate a s judged by the Bergmann-Junk test. The stability of glycogen nitrate is closely similar to that of amylopectin nitrate.Appreciable stabilization of the crude nitrates mas brought about by boiling with slightly allcaline water for long periods (60-70 hours). All stabilized samples were found to possess closely si~uilar stability properties. The Bergmann-Junk values of all examined nitrates ranged from 2.2 to 1.7 mg of nitrogen per gram sample; the latter value seems to represent the maximum stabilization which could be attained for the polymeric carbohydrate nitrates of the a-D-glycosidic linkage type. In the case of cellulose nitrate (6-D-glycosidic linkage type) Bergmann-Junk values of 1 to 1.25 mg of nitrogen were obtained.