The invention provides a compound which has anti-ulcer effect and antibacterial activity against Helicobacter pyroli. This compound is an alkylenediamine derivative or salt which has a general formula of (1): ##STR1## wherein each of R.sub.4, R.sub.5, and R.sub.6 is hydrogen or lower alkyl; n represents an integer of 1 to 6; Y is --CH.sub.2 --, --O--, or --N(R.sub.7)--, wherein R.sub.7 is lower alkyl, aryl, carbamoyl lower alkyl, aralkyl, or a heterocyclic group having 5 to 9 carbon numbers; and, W is a group expressed by formulas 2 or 3: ##STR2## wherein (1) in formula 2: each of R.sub.1 and R.sub.2 is hydrogen, lower alkoxy, alkenyloxy, or a halogen atom; each of R.sub.3 and R.sub.3 is methyl, prenyl, or geranyl; when one of R.sub.3 and R.sub.3 is prenyl or geranyl, the other must be a methyl group; and X is oxygen or sulfur; and (2) in formula 3, R.sub.10 is a lower alkyl, and R.sub.11 is a halogen atom.