The present invention relates to a piperidine compound represented by the formula [I]: ##STR00001## wherein Ring A represents an optionally substituted benzene ring, Ring B represents an optionally substituted benzene ring, R.sup.1 represents an optionally substituted hydoxyl group, a substituted thiol group, a substituted sulfonyl group, etc., or a group represented by the formula: ##STR00002## R.sup.11 represents a substituted carbonyl group or a substituted sulfonyl group, R.sup.12 represents hydrogen atom or an optionally substituted alkyl group, R.sup.2 represents hydrogen atom, etc., Z represent oxygen atom or a group represented by --N(R.sup.3)--, R.sup.3 represents an optionally substituted alkyl group, etc., R.sup.4a represents an optionally substituted alkyl group, R.sup.4b represents an optionally substituted alkyl group, or a pharmaceutically acceptable salt thereof, having an excellent tachykinin receptor antagonistic action.