Grating structures of gold nanowires with a width of sub-100 nm and a total area in the order of square centimeters are prepared using interference lithography and colloidal gold nanoparticles.In the fabrication, photoresist is firstly spin-coated onto the glass substrate that is coated with a layer of indium tin oxide as thick as 200 nm.Grating structures are then produced by interference lithography into the photoresist.Through controlling the exposure dose and the development time, small duty cycles are achieved with the photoresist gratings.Thereafter, colloidal gold nanoparticles are spin-coated onto the photoresist master grating.Making use of the dewetting properties of the colloidal solution on the photoresist surface, very limited amount of gold nanoparticles remain on the photoresist grating and are confined into the grating grooves.In combination with the small duty cycle of the photoresist grating structures, this mechanism enables realization of narrow gold nanowires.In the final stage of the fabrication, the sample is heated to 250℃ for about 5 minutes.Gold-nanowire gratings with a duty cycle of 1: 4 and a period of 400 nm are achieved, which have an effective area of 1 cm2.The optical response featured with strong coupling between the waveguide resonance mode and particle plasmon resonance confirms the successful fabrication of the waveguided metallic photonic crystals.This device may be utilized as the central part of the biosensors with small sensing volumes.