Abstract: The particle size and distribution of emulsions are closely related to the emulsifying properties of emulsions. In order to prepare arabinoxylan from wheat bran with excellent emulsifying properties,the average particle size and distribution were investigated to study the influence of temperature and time of alkaline extraction,concentration of NaOH and pH on the emulsion particle size of emulsion,and orthogonal experimental method was used to optimize the extraction conditions. Results indicated that when the extracting temperature 85 ℃,time 180 min,concentration of NaOH 0.15 mol/L,pH4.3 respectively,the arabinoxylan emulsion reached the minimum average particle size(0.4859±0.009 μm)lower than that of the Arabic gum(0.5494±0.013 μm),and with similar polydispersity index(0.147±0.015,0.113±0.016,p=0.208>0.05). Therefore,preparation of wheat bran arabinoxylan with an emulsifying property of superior or close to the Arabic gum by optimizing the extraction conditions is feasible and provide theoretical reference for industrial production of the arabinoxylan.