The investigation explores the fabrication and characteristics of ZnO nanowire/ p-GaN/ ZnO nanowire heterojunction light emitting diodes (LED). Vertically aligned ZnO NWs arrays were grown on the p-GaN substrate by thermal chemical vapor deposition. The n-p-n heterojunction LED was successfully fabricated by combining ITO/glass substrate with the prepared ZnO nanowires /p-GaN substrate. The symmetrical rectifying behavior demonstrates that the heterostructure herein was formed with two p-n junction diodes and connected back to back. The room-temperature electroluminescent (EL) emission peak at 415 nm was attributed to the band offset at the interface between n-ZnO and p-GaN and defect-related emission from ZnO and GaN. Finally, the photograph indicated the LED clearly emitted blue light.