Provided is a composition for intraoral massage that is excellent in dispersibility at the initial stage of massage in the oral cavity and retentivity in the mucous membrane, and is not easily dropped from an intraoral massage device. The composition includes a component (A) which is either one or both of sodium dihydrogen phosphate and sodium monohydrogen phosphate； a component (B) which is sodium alginate； a component (C) which is either one or both of xanthan gum and sodium polyacrylate in a specific ratio. The viscosity of the composition at 25 °C is 5,000 to 20,000 mPa·s. When the composition is diluted 3-fold with artificial saliva, the viscosity at 25 °C is 100 to 1,000 mPa·s. An intraoral massage set includes a pump-type container containing the composition and an intraoral massage device 1.本發明提供一種於口腔內的按摩初期的分散性、以及相對於黏膜的滯留性優異、且難以自口腔內按摩器垂落的口腔內按摩用組成物、裝入口腔內按摩用組成物的容器、口腔內按摩套組。一種口腔內按摩用組成物，以特定比率含有（A）成分：磷酸二氫鈉及磷酸一氫鈉的任一者或兩者、（B）成分：海藻酸鈉、以及（C）成分：三仙膠及聚丙烯酸鈉的任一者或兩者，且25℃下的黏度為5000 mPa·s～20000 mPa·s，由人工唾液稀釋3倍時的25℃下的黏度為100 mPa·s～1000 mPa·s。一種口腔內按摩套組，包括：於泵型容器中填充有所述口腔內按摩用組成物的裝入口腔內按摩用組成物的容器、以及口腔內按摩器1。
