The present invention relates to a compound represented by the formula: wherein Ar is a phenyl group optionally having substituent(s), R.sup.1 is a hydrogen atom, a hydrocarbon group optionally having substituent(s), an acyl group or a heterocyclic group optionally having substituent(s), R.sup.2 is a hydrogen atom, a C.sub.1-6 alkyl group optionally having substituent(s) or a C.sub.3-6 cycloalkyl group optionally having substituent(s), Z is a methylene group optionally having a C.sub.1-6 alkyl group, ring A is a piperidine ring optionally further having substituent(s), ring B and ring C are benzene rings optionally further having substituent(s), and R.sup.2 optionally form a ring together with the adjacent substituent on the ring B, except the compounds represented by the formula: or a salt thereof. The compound of the present invention has a superior tachykinin receptor antagonistic action, particularly a substance P receptor antagonistic action, and is useful as a pharmaceutical agent, for example, tachykinin receptor antagonist, an agent for the prophylaxis or treatment of lower urinary tract symptoms, gastrointestinal diseases or central nerve diseases.