In this study， reaction system of adipoxygenase catalyze linoleic acid was selected as representative of lipid hydroperoxide. And walnut proteins of oxidative modification by lipid hydroperoxide were prepared. To evaluate the effect of different linoleic acid content on the walnut protein structure， protein carbonyl value， free sulfhydryl particle size distribution were determined. The emulsion was prepared from the modified walnut separation protein and the emulsion properties were evaluated. Emulsifying activity， emulsifying stability， the particle size distribution， the fluorescence and the microstructure of emulsions were evaluated. The result showed that No-oxidized walnut protein （control） contained 2.32 nmol carbonyls/mg proteins. There was a 2.32 nmol/mg to 4.23 nmol/mg increase in carbonyl groups when the linoleic acid content was increased compared with no-oxidized samples. The results indicated that the formation of carbonyls in walnut protein was sensitive due to oxidation concentration changed. Protein oxidation is also accompanied by a decrease in free sulfhydryl groups. Oxidated walnut protein with increasing content of linoleic acid resulted in a significant declining（P<0.05） in free sulphydryl and total disulphide / sulphydryl. The hydrophobic interactions are considered to play important roles in the functional properties of food proteins. Therefore， surface hydrophobicity could induce changes in functional properties of oxidized walnut protein. The result showed that gradual decrease in surface hydrophobicity with the increase of linoleic acid content. The results of emulsifying ability index （EAI） and emulsion stability index（ESI） of hydrogen peroxide oxidation walnut proteins results clearly demonstrated that oxidation resulted in an improvement in the emulsion capacity of walnut protein at the lower oxidation concentration， and the emulsion activity index（EAI） and emulsion stability（ESI） of non-oxidized SPI were 74.66 m2/g and 20.9%， respectively. Both indices were improved with a lower content of linoleic acid. The average particle size were increased with soluble aggregate turned into insoluble aggregates as the degree of oxidation increased and the conformational change of the emulsion were detected by fluorescence spectroscopy. The emulsion oil droplet size distribution were different with the different oxidation degree. Because moderate oxidation lead to more hydrophobic groups exposed and to form soluble polymer， the surface area of the emulsion droplet size distribution average diameter was reduced and emulsifying activity was improved. Further oxidation were promoted to the aggregation of droplets and resulted in poor emulsifying activity. The Pearson correlation coefficient was established between the structure and the emulsifying function index. The results showed that the changes of protein structure caused by HPODE oxidation were not significant in the emulsification of walnut protein.