2-Substituted-N-{3-[3-(1-piperidinomethyl)phenoxy]propyl}acetamide, derivatives thereof, and pharmaceutically acceptable salts thereof. The substitution group may be aminomethylcyclohexane carbonyl group or N-carbobenzoxy-p-aminomethylhexane carbonyl group. The compounds having the first-mentioned group can be an effective component of an antiulcer drug composition, and the compounds of the last-mentioned group are intermediates for producing the compounds having the first-mentioned group. Disclosed also is an antiulcer drug composition comprising the above compound as an effective component. The antiulcer drug composition exhibits both the gastric acid secretion inhibitive activity and the gastric mucosa protective activity, and is effective as suppression and cure of ulcers.