A grouting material which comprises an ultrafine particle material having a maximum particle size of 15 micrometer or less, containing 3 to 40% by mass of cement clinker, 60 to 97% by mass of and blast-furnace slag, 0.5 to 3 parts by mass of gypsum in terms of SO.sub.3 based on 100 parts by mass of the total amount of cement clinker and blast-furnace slag, and further comprises (i) 0.7 to 7 parts by mass of calcium-aluminate-based rapid-hardening admixture, (ii) 0.01 to 0.13 parts by mass of setting retarder, and (iii) 0.2 to 1.0 parts by mass of high-performance water-reducing agent, based on 100 parts by mass of the ultrafine particle material can maintain high injectability for long, and rapidly starts to set after injected to thereby exhibit a good short-term strength.