A highly conductive transparent anode was fabricated by solution metho d based on poly(3,4- ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/graphene oxide (GO) hybrid film by sulfuric acid (H₂SO₄) treatment.The optimal treated PEDOT:PSS/GO films reach a sheet resis tance of 80Ω/□ per square and a high transmittance of 87.7% at 550nm.Based on the atomic force microscopy,abso rption and Raman spectrum,the structures of PEDOT:PSS was changed after the small amount of GO doping and H₂SO_4treatment,which led to the separation of PSS and PEDOT chains and the enhancement of the conductivity of hy brid films.The ITO free OLEDs fabricated with the optimized PEDOT:PSS/GO film as anode has the lowest turn-o n voltage and highest current efficiency in comparison with ITO anode and pure PEDOT:PSS anode based OLEDs.A t the same time,the brightness of OLEDs with the optimized hybrid film anode is 1.7times higher tha n that of OLEDs with pure PEDOT: PSS anode.All of the higher transmittance,higher conductivity and higher HOMO levels,especially the variation of topography,ascribed to the improved efficiency of OLEDs with hybrid film ano de.