Nitration of ammonium sulphamate was carried out using a mixture of sulphuric acid and nitric acid at -30 to -40degreesC. The mole ratio of sulphuric acid to nitric acid was varied from 0 to 4 and the extent of formation of ammonium dinitramide (ADN) was measured. The initial yield of ADN increases with increase of sulphuric acid content in the acid mixture and starts decreasing as the reaction time is increased. The variation of product yield with change in reaction time and total acid concentration was studied.