Al0. 3 Ga0. 7N /GaN and AlN /GaN distributed Bragg reflectors (DBR ) with a target center wavelength of 500nm were designed, and simulation with a transfer－matrix－method ( TMM) was performed to give their spectral re－ flectivity. The corresponding two samp leswere grown bymetal－organic－chemical－vapor－deposition (MOCVD) on sap－phire substrate. It shows from the measured reflectivity spectrum of each samp le that obvious reflectance peak occurs, but the centerwavelength has some deviation from the designed value and the peak reflectance value is lower than ex－ pected. These attribute to the variation of the real layer thickness and the uneven interfaces, which can be app roved from the SEM and AFM measurement.