The research progress of Ⅲ-Nitride promotes the development and the app --lication of all kind GaN-based devices. Especially, the GaN-based ultraviolet photo-detector can adjust the cut-off wavelength through changing the Al content in the AlxGa1 - xN materials. And the AlxGa1 - xN with high Al content can be used to fabricate the solar-blind photo-detectors, which induces our attention greatly. The basic characters of the ultraviolet photo-detector, including the ultravioletwavelength and atmosphere absorp tion, etc, are presented briefly. Then, the GaN2based Photo-detector device research progress is reviewed, such as the P2GaN dop ing,metal-semi contact and etching problems, etc. Finally, the resent developments of the ultraviolet detector, especially the ultraviolet FPA, are introduced.