AlGaN/GaN heterostructures on vicinal sapphire substrates and just-oriented sapphire substrates (0001) are grown by the metalorganic chemical vapor deposition method.Samples are studied by high-resolution x-ray diffraction,atomic force microscopy,capacitance-voltage measurement and the Van der Pauw Hall-effect technique.The investigation reveals that better crystal quality and surface morphology of the sample are obtained on the vicinal substrate.Furthermore,the electrical properties are also improved when the sample is grown on the vicinal substrate.This is due to the fact that the use of vicinal substrate can promote the step-flow mode of crystal growth,so many macro-steps are formed during crystal growth,which causes a reduction of threading dislocations in the crystal and an improvement in the electrical properties of the AlGaN/GaN heterostructure. AlGaN / GaN heterostructures on vicinal sapphire substrates and just-oriented sapphire substrates (0001) are grown by the metalorganic chemical vapor deposition method. Samples are studied by high-resolution x-ray diffraction, atomic force microscopy, capacitance-voltage measurement and the Van der Pauw Hall-effect technique. The investigation reveals that better crystal quality and surface morphology of the sample are obtained on the vicinal substrate. Future, the electrical properties are also when the sample is grown on the vicinal substrate. this is due to the fact that the use of vicinal substrate can promote the step-flow mode of crystal growth, so many macro-steps are crystal during growth, which causes a reduction of threading dislocations in the crystal and an improvement in the electrical properties of the AlGaN / GaN heterostructure.