Poly(3,4-ethylenedioxythiophene) (PEDOT) nanorods (80-150 nm in diameter) and nanospheres were synthesized through a self-assembly method using ferric chloride (FeCl(3)) and ammonium persulfate (APS) as oxidants, respectively, and camphorsulfonic acid (CSA) as the dopant. The PEDOT nanorods showed broader absorption bands, higher crystallinity and much higher room-temperature conductivity (approximately 300 S cm(-1)) than the PEDOT nanospheres. Such obviously distinct properties of these products were considered to be due to the much lower rate of polymerization with FeCl(3) than APS, which made the growth of PEDOT according to the suggested cylinder micelles more moderate and regular; as a result, the morphology of the microstructure changed and the crystallinity, the doping level, the molecular orderliness and the conductivity of PEDOT synthesized under lower rate of polymerization improved intensely at the same time.