Abstract: The anaerobic degradation of ascorbic acid in neutral injection has been studied. Some degradation products as 2-keto-L-gulonic acid and xylose were identified by using of TLC. A new degradation product pyruvaldehyde was isolated and identified as 2,4-dinitrophenylhydrazone. The amount, of 2-keto-L-gulonic acid formed from degradation of ascorbic acid in injection and amount of carbon dioxide produced from that of ascorbic acid and 2-keto-L-gulonic acid were determined. From these, the pathway for the anaerobic degradation of ascorbic acid in neutral injection Was proposed.