Design and growing 12.5 period Al 0.6 Ga 0.4 As/AlAs distributed Bragg reflection (DBR) structure by MOCVD on (311) GaAs substrates.By white light reflection mapping,the peak reflect wavelength uniformity is about 1.0 %,and absolute reflection of these DBR can reach above 90 %,The structure was investigated by double crystal X ray diffraction,and the DBR period of 84.5 nm for 580 nm wavelength was obtained.