Anion-exchange studies have revealed that beryllium forms anionic complexes with fluoride, phosphate, carbonate, and thiocyanate, the stabilities of these complexes lie in the order F-> H2P04- = CO3 = >> CNS-. Under the conditions of this investigation BeF4-2 and Be (H2P04)4-2 have been identified. Attempts to identify the carbonate complex were prevented by hydrolysis. The anionic thiocyanate complex is very weak and no attempt was made to identify this species. The anion -exchange data obtained in dilute nitric, hydrochloric, and sulphuric acid solutions showed some anionic complex formation but corresponding cation -exchange data have shown that in solutions of concentration up to 2.0M the extent of this reaction is negligible.