Stimuli-responsive or controlled self-assembly has been intensively investigated over the years for various applications such as bio-sensing, drug delivery and actuators. Hydrazone functional group has advantage to be applied in stimuli-responsive materials due to its dynamic property of the reversible C=N bond. We will discuss here novel pyridinium hydrazone conjugates which show concentration-dependent equilibrium between a hydrazone and a merocyanine. This phenomenon was occurred by protonation/deprotonation equilibria which is affected by the formation of a dimer or aggregates. We also observed similar pH-responsive characteristic of di- and tri(pyridinium hydrazone) conjugates. Interestingly, di- and tri(pyridinium hydrazone) conjugates showed wire-type self-assembly, which was evident in scanning electron microscopy (SEM) and atomic force microscopy (AFM). The self-assembly of the pyridinium hydrazone conjugates could be controlled by pH variation and dynamic exchanges.