To provide a technique that improves the stability of brimonidine in an aqueous composition.SOLUTION: An aqueous composition contains following components (A) and (B): (A) brimonidine or a salt thereof or their solvates; and (B) an amino compound.SELECTED DRAWING: None【課題】水性組成物中の、ブリモニジンの安定性を向上させる技術の提供。【解決手段】次の成分(A)及び(B):(A)ブリモニジン若しくはその塩又はそれらの溶媒和物;(B)アミノ化合物;を含有する、水性組成物。【選択図】なし