The present invention relates to an aqueous composition containing cyanocobalamine and received in a plastic container which is formulated with at least one compound selected from the group consisting of benzotriazole-based compounds, hydroxyphenyl triazine-based compounds and hindered amine-based compounds. The present invention also relates to a stabilization method of cyanocobalamine, which is processed by taking the cyanocobalamine-containing aqueous composition to be received in a plastic container which is formulated with at least one compound selected from the group consisting of benzotriazole-based compounds, hydroxyphenyl triazine-based compounds and hindered amine-based compounds.本發明係關於一種水性組合物，其係含氰鈷胺者，且收容於調配有選自由苯并三唑系化合物、羥基苯基三?系化合物及受阻胺系化合物所組成之群中之至少一種化合物的塑膠製容器中；及一種氰鈷胺之安定化方法，其係藉由將含氰鈷胺之水性組合物，收容於調配有選自由苯并三唑系化合物、羥基苯基三?系化合物及受阻胺系化合物所組成之群中之至少一種化合物的塑膠容器中而進行。
