The organic NTC composition according to the present invention is a mixture of a conjugated organic semiconductor polymer and a thermoplastic resin or thermosetting resin. For example, the mixed amount of the thermoplastic resin or thermosetting resin is preferably equal to or lower than two times the amount of the conjugated organic semiconductor polymer, and a conjugated organic semiconductor polymer selected from solvent-soluble polyaniline, polythiophene, polypyrrole and their derivatives is preferably used.This organic NTC composition makes it possible to provide an organic NTC device without using any expensive material and facilitates easy production at low temperatures.