NOVELTY - A conductive formulation comprises organic semiconductor compound (OSC), organic solvents(s) and conductive additive(s) (0.5 weight% or less). The conductive additive increases the conductivity of the formulation, and is volatile and/or does not chemically react with organic semiconductor compound.    USE - Conductive formulation is used as printing ink for preparing organic electronic devices such as organic field effect transistor, integrated circuit, thin film transistor, radio frequency identification tag, organic light emitting diode, organic light emitting transistor, electroluminescent display, organic photovoltaic cell, organic solar cell, flexible photovoltaic cell, organic laser diodes, organic integrated circuits, lighting device, sensor device, electrode material, photoconductor, photodetector, electrophotographic recording device, capacitor, charge injection layer, schottky diode, planarizing layer, antistatic film, conducting substrate, conducting pattern, electrophotographic devices organic memory device, biosensor and biochip (all claimed).    ADVANTAGE - The formulation has excellent conductivity, and provides organic electronic devices having excellent performance.    DETAILED DESCRIPTION - A conductive formulation comprises organic semiconductor compound (OSC), organic solvents(s) and conductive additive(s) (0.5 weight% or less). The conductive additive increases the conductivity of the formulation, and is volatile and/or does not chemically react with organic semiconductor compound. The conductive additives are chosen from non-oxidizing organic salt, volatile organic salt, alcohol, volatile carboxylic acid and organic amine. The non-oxidizing organic salt and volatile organic salt are chosen from quaternary ammonium salt, phosphonium salt, imidazolium salt and heterocyclic salt. The anion of non-oxidizing organic salt and volatile organic salt is chosen from halide, sulfate, acetate, formate, tetrafluoroborate, hexafluorophosphate, methanesulfonate, triflate (trifluoromethane sulfonate) and bis(trifluoromethyl sulfonyl)imide. The alcohol is isopropyl alcohol, iso-butanol, hexanol, methanol and/or ethanol. The volatile carboxylic acid is formic acid, acetic acid, difluoroacetic acid or trifluoroacetic acid. The organic amine is primary alkyl amine or secondary alkyl amine. The conductive formulation further comprises solvent (1) such as toluene, o-xylene, m-xylene or p-xylene, trimethyl benzene, tetralin, anisole, alkyl anisole, naphthalene and alkyl naphthalene, and carrier solvent chosen from cyclopentanone, acetonitrile, benzonitrile, nitromethane, tetrahydrofuran and acetone. The OSC compound is substituted polyacene and/or poly(3-substituted thiophene), and comprises p-type OSC compound and n-type OSC compound.