PROBLEM TO BE SOLVED: To provide an oral composition having a biofilm formation suppression activity.SOLUTION: The oral composition containing a plant extract, preferably the hot water extract of komatsuna (Brassica Rapa var. perviridis), mizuna (Brassica rapa var. nipposinica), mibuna (Brassica campestris var. laciniifolia), karami daikon (Raphanus sativus var. longipinnatus), cress, ostrich fern, Aralia elata, or ice plant.COPYRIGHT: (C)2013,JPO&INPIT【課題】バイオフィルム形成抑制作用を有する口腔用組成物の提供。【解決手段】小松菜、水菜、壬生菜、辛味大根、クレス、コゴミ、タラノキ、またはアイスプラントの熱水抽出物である植物抽出物を含有する口腔用組成物。【選択図】図2