Abstract:A new food-grade hydrophobically modified oat starch-based stabilizer for Pickering emulsion was developed to enrich the utilization of oat starch. Oat starch was extracted from oat. Oat starch was modified with octenyl succinic anhydride （OSA） to obtain OSA-hydrophobic modified oat starch， and the Pickering emulsion was prepared based on OSA-hydrophobic modified oat starch. The results of optical microscope analysis，particle size determination， Zeta potential determination， and emulsification index were taken as the indicators to evaluate the effects of hydrophobic modification degree， particle concentration， volume ratio of oil to water， pH， and ion concentration on the stability of Pickering emulsion. The results showed that the stability of hydrophobically modified oat starch was much higher than that of naked oat starch. The stability of the emulsion increased with the increase in the modification degree and did not change obviously after the modification degree increased beyond 3.46%. The stability of the emulsion was the best （maintaining for 28 days） when the particle concentration increased to 2.0%， and further increases in concentration caused no significant change in the stability. The emulsion was difficult to maintain stable with a high proportion of oil phase. The emulsion based on OSA-modified oat starch basically maintained stable when the volume ratio of oil to water was less than 1. When the volume ratio of oil to water was lower than 0.8， the emulsion maintained stable within 28 days.The emulsion maintained stable within pH3-9， and the stability of the emulsion enhanced gradually when the pH changed from acidity to mild alkalinity. The emulsion showcased decreased stability with the increase in ion concentration， remaining stable within the ion concentration of 1.0 mol/L. Key words： oat starch； octenyl succinic anhydride； hydrophobic modification； Pickering emulsion； emulsion stability