An object of the present invention is to promote penetration of a compound having a Rho kinase inhibitory activity to a topical moiety, and provide an aqueous liquid preparation capable of maintaining a given drug concentration even when administration frequency is reduced. The present invention solves the aforementioned problem by an aqueous liquid preparation containing a compound represented by the following formula (I) ##STR00001## wherein each symbol is as defined in the specification, an isomer thereof and/or a pharmaceutically acceptable acid addition salt thereof, and an ion-pairing reagent or a water-soluble polymer.