To provide a new safe foaming agent or cosmetic composition.

This foaming agent or cosmetic composition is characterized by containing one or more plant extracts selected from the plant extracts of Akebia quinata (Houtt.) Decne., Gynostemma pentaphyllum (Thunb.) Makino, Polygala tenuifolia Willd., Lindera strychnifolia (Sieb. et Zucc.) F. Vill. (=Benzoin strychnifolium (Sieb. et Zucc.) O. Kuntze), Panax ginseng C. A. Meyer (=P.schinseng Nees), Glycyrrhiza glabra Linne, G. glabravar. Glandulifera, G. uralensis Fisher), (G. kansuensis Chang et Peng), (G. pallidiflora Maxim.), Gentiana lutea Linne, Trigonella foenum-graecum L., Alisma plantago-aquatica L. subsp. orientale Samuelsson (=A. plantago-aquatica L. var. orientale Samuelsson, A. orientale Juzepczuk, A. plantago var. parviflorum), Saponaria officinalis Linne, Cimicifuga simplex Wormsk., Hedera helix L., Aesculus hippocastanum, Polygala senega L., Aralia elata (Miq.) Seem., Syzygium aromaticum (L.) Merrill et Perry (=Eugenia caryophyllata Thunberg), Centella asiatica (L.) Urban (=Hydrocotyle asiatica L.), Benincasa hispida (Thunb.) cogn.(=B. cerifera Savi, B. cerifera Savi forma emarginata K. Kimura et Sugiyama), Panax japonicus C. A. Mey. (=P. schinseng Nees var. japonicum (C. A. Mey.) Makino, Agaricusblazei Murrill, Eriobotrya japonica (Thunb.) Lindley, and Sapindus mukurossi Gaertner. It is confirmed that the foaming agent or cosmetic composition has excellent foamability and good foam-retaining stability. Thereby, the foaming agent is effective for improving the stability of the cosmetic composition, after prepared, and further for improving the touch and convenience of the cosmetic composition, when used, and is safe for the skins.