The author studied the action of autonomic drugs on the urinary bladder isolated from Ditrema temmincki Bleaker and the results obtained were summarized as follows: 1) The motility of the urinary bladder of the fish was stimulated by acetylcholine and physostigmine. The stimulating action of these drugs was antagonized by atropine. 2) The motility of the fish bladder was stimulated by epinephrine, nor-epinephrine and phenylephrine, but inhibited by isoproterenol. 3) The inhibitory effects of isoproterenol on the fish bladder was not affected by phenoxybenzamine, but blocked by propranolol. 4) The excitatory effects of phenylephrine on the fish bladder were blocked by phenoxybenzamine, but augmented by propranolol. 5) The excitatory effects of epinephrine and nor-epinephrine were reversed by phenoxybenzamine and augmented by propranolol. 6) The motility of the fish bladder pretreated with phenoxybenzamine and propranolol was not affected by isoproterenol, phenylephrine, epinephrine and nor-epinephrine. 7) It seemed that the bladder muscle of the fish had both alpha excitatory and beta inhibitory receptors. 8) The motility of the fish bladder was stimulated by nicotine and DMPP. The excitatory effects of these drugs were abolished by pretreatment with hexamethonium or atropine. 9) It is, therefore, concluded that there are ganglion cells furnished with cholinergic fiber in the bladder wall of the fish.