Abstract: The conductivity of polythionine is 9.6×10－6 S•cm－1,which is an organic semiconductor.The cyclic voltammograms,discharging curves at a constant potential,ac impedance plots of polythionine and the conductivity of the electrolyte solution were investigated.There are an anodic peak and a cathodic peak in the cyclic voltammogram of polythionine.Their peak currents increase with increasing temperature.The discharging current at constant potential also increases with increasing temperature.The result from ac impedance plots shows that the charge transfer resistance Rct decreases with increasing temperature,i.e.,its exchange current i0 increases with increasing temperature.The resistances of the solution and the film decrease with increasing temperature.These also cause the increase in the current with increasing temperature.Thus,the effect of temperature on the reaction rate of polythionine semiconductor contains several factors of the electrode reaction itself and the conductivity of polythionine etc..The scanning electronic micrograph shows that the surface of polythionine is a fibrillarlike morphology.