To obtain a wet grout material having excellent dispersibility into a liquid, pourable by a wet method into the deep part of a target part under a relatively low pressure, having a high hardening rate, capable of developing strength in its early stages and to provide a method for readily producing the grout material in stable qualities.

This wet grout material comprises mixed particles of (A) a hydraulic composition obtained by adding a gypsum to a baked material which has 2-7 μm average particle diameter, ≤10 μm maximum particle diameter and ≤10 wt.% of existence ratio of particles having <1 μm, is obtained from incinerated ash of municipal refuse and is composed of a precipitated hydraulic component and (B) blast furnace slag and is obtained by heating in a nonoily organic solvent with stirring.