NEW MATERIAL:A compound expressed by formula I (Het is substitutive heterocyclic ring; X is single bond or NH) or salts thereof. EXAMPLE:5-[(1-Methylindol-3-yl)carbonyl]-4,5,6,7-tetrahydrobenzimidazole. USE:Useful as a therapeutic agent for nausea, hemicrania, complex cephalalgia, prosopalgia, anxiety symptoms, gastrointestinal dyskinesia, peptic ulcer, etc. PREPARATION:An amine, amide or urea expressed by formula III (X is single bond or NH) is subjected to a reaction with 4,5,6,7-tetrahydrobenzimidazole-5- carboxylic acid expressed by formula II or a reactive derivative thereof to afford the objective compound expressed by formula Ia.