High performance p-GaN/oxide layer/n-GaN ultraviolet (UV) photodetector was fabricated in this paper. The UV detector composed of n-GaN and p-GaN film with oxide layer which was constructed by directly contacting way. The detector based on GaN p-GaN/oxide layer/n-GaN structure showed high UV response with fast speed. The results indicated that the fabrication of large-scale GaNbased materials was greatly facilitated with relatively low cost contacting method. Furthermore, it offered a new method to obtain UV detector for GaN-based materials with high performance.