the present invention relates to a conductive polymer composition which exhibits ptc characteristics and a ptc device comprising it , wherein the ptc composition comprises : a ) at least one crystalline olefin - based polymer and at least one ionomer ; and , b ) electrically conductive particles which have been dispersed in polymer matrix formed by a ). the ptc composition according to the present invention has an enhanced adhesion to electrodes , which minimizes contact resistance and increases the maximum working current . the ptc device comprising the ptc composition can be used as a circuit protection device which protects circuit from overflowing and which holds initial resistance value although it is reused after multiple short circuit have taken place .