Quinoline derivatives of the formula, ##STR1## wherein > A represents a group >N--(CH.sub.2).sub.n --, >C.dbd., >C.dbd.CH(CH.sub.2).sub.n --, or >CH(CH.sub.2).sub.n --, wherein n is an integer of 0-7; Y represents a group >C.dbd.O or >CHOH, R.sup.1 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an alkylthio group, R.sup.2 is a hydrogen atom, a halogen atom, an alkyl group, a hydroxy group, an alkoxy group, a phenyl group which may have a substituent, a phenoxy group, an alkanoyloxy group, or an amino group which may have a substituent, R.sup.3 is a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group, and m is an integer of 1-3. The compounds and their salts exhibit a superior antiacetylcholinesterase activity with no side effects and are effective for the prevention or cure of senile dementia or memory disturbance.