Poly(3,4-Ethylenedioxythiophene)(PEDOT)is one of the most stable conduct in conducting polymers. In this paper, preparation methods of 3,4-Ethylenedioxythiophene(EDOT)and its polymer(PEDOT)are reviewed. Applications of PEDOT in antistatic, electrolytic capacitor, organic optoelectronic materials and sensor are investigated as well.