A quinuclidine derivative represented by general formula (I), a salt, N-oxide or quaternary ammonium salt thereof, and a medicinal composition containing the same, wherein the ring A represents optionally substituted aryl, cycloalkyl, cycloalkenyl, heteroaryl containing 1 to 4 heteroatoms selected from among oxygen, nitrogen and sulfur, or 5- to 7-membered saturated heterocycle; X represents a single bond or methylene; R represents halogeno, hydroxy, lower alkoxy, carboxy, lower alkoxycarbonyl, lower acyl, mercapto, lower alkylthio, sulfonyl, lower alkylsulfonyl, sulfinyl, lower alkylsulfinyl, sulfonamido, lower alkanesulfonamido, carbamoyl, thio-carbamoyl, mono- or di(lower alkyl)carbamoyl, nitro, cyano, amino, mono- or di(lower alkyl)amino, methylenedioxy, ethylenedioxy or lower alkyl optionally substituted by halogeno, hydroxy, lower alkoxy, amino or mono- or di(lower alkyl)amino; 1 is 0 or 1; m is an integer of 1 to 3; and n is an integer of 1 or 2. The compound has an antagonistic effect on muscarine M3 receptors and is useful as a preventive or remedy for urologic diseases, respiratory diseases or digestive diseases.