Abstract: More stable prussian blue modified platinum electrodes which can underyo over one thousand cycles of potential sweep between +0.6V and +1.1V(Vs, SCE) have been made.A model of electron transfer during the electrochemical redox process of the PB film has been proposed. The effects of preparation conditions, film thickness and the pH value of supporting electrolyte solution on voltammetric behaviour of the electrode have been stu-died systemmatically.