Provided is an aqueous composition contained in a container, maintaining an excellent water-evaporation-inhibiting effect even when an alkali metal salt or the like is contained in the aqueous composition, and having excellent long-term stability. The aqueous composition contained in a container includes the following components (A) to (D): (A) a polyoxyethylene alkyl or alkenyl ether having an alkyl or alkenyl group having 20 to 24 carbon atoms and an average molar number of ethylene oxide added of 1.5 to 4, (B) a water-soluble polymer, (C) a nonionic surfactant having an ethylene oxide group (but excluding component (A)), and (D) water.本發明提供一種容器裝之水系組合物,其即便於前述容器裝之水系組合物中調配有鹼金屬鹽等之情形時,亦可維持優異之水分蒸散抑制效果,且經時穩定性優異。本發明之容器裝之水系組合物含有如下成分(A)~(D):(A)烷基或烯基之碳數為20~24且環氧乙烷之平均加成莫耳數為1.5~4之聚氧乙烯烷基或烯基醚、(B)水溶性高分子、(C)具有環氧乙烷基之非離子性界面活性劑(其中,(A)成分除外)、及(D)水。
