The charge transport property of G4 DNA molecule that represented mathematically by using Hamiltonian tight binding approach has been studied. Charge transport property in the model of 102 base pairs long G4 DNA is studied from localization length under influence of electric field and temperature. Electric field affects electron hopping constants in G4 DNA molecule, while temperature leads to DNA structural disorder. Localization length is calculated by using transfer matrix method and using gram-schmidt orthonormalization method to reduce calculation errors. The result show, the increment of electric field and temperature decreases localization length, so that G4 DNA molecules becomes less conducting. © Published under licence by IOP Publishing Ltd.