Abstract: Polybenzidine micro/nano particles were prepared using micelles of diblock copolymer PEO-b-P4VP as templates. A series of polybenzidine micro/nano particles with tunable morphology and size were obtained by a simple way of just regulating pH value of the micellar solution of templates. FT-IR spectroscopy, ¹H-NMR, transmission electron microscopy, cyclic voltammetry, constant current charge-discharge and electrochemical impedance were used to characterize the structures, morphologies and electrochemical properties of samples. The polybenzidine particles both induced by block copolymer template and obtained after removing the template were all rod like particles with average diameters below 200 nm, and they all had a uniform morphology and size distributions. Decreasing pH value of the micellar solution of templates led to the increase of polybenzidine particle size. Except the minor change in diameter size, the morphologies of polybenzidine had no change after removing the template. Results of electrochemical test showed that polybenzidine particles had good electrochemical activities. The specific capacitance of polybenzidine particles reached 306.3 F/g at the current density of 1 A/g. The capacity decline rates of samples were very small after 500 charge-discharge cycles, indicating the good cycling stability.The electrochemical properties of samples showed the tendency of increasing with the decrease of their diameters.