A mucosal adjustment material comprising a combination of a powdery material (a) and a liquid material (b), characterized especially in that a noncrosslinked (meth)acrylic polymer powder having a Tg in the range of 0-60 DEG C, e.g., polybutyl methacrylate, is used as the powdery material and a liquid polymer which has a mass-average molecular weight of 1,000-10,000 and in which the content of oligomers having a molecular weight of 500 or lower is 10 mass% or lower is used as the liquid material. Such powdery material and liquid material are kneaded together to prepare a paste, which is applied to a denture base and used as a temporary relining material. This mucosal adjustment material in a paste form is reduced in the amount of ingredients eluted from the material during use in the mouth. In an ordinary use period, the relining material retains its initial flexibility and does not deteriorate the denture base.