Abstract: In order to investigate the effects of soybean protein nanoparticles composed of different 7S subunits on β-carotene Pickering emulsion. In this study, wild type soybean（Wild）, α subunit deletion soybean（α-lack）, α′ subunit deletion soybean（α′-lack） and（α+α′） subunit deletion soybean（α+α′）-lack were used as raw materials to extract soybean protein isolate（SPI）. β-carotene Pickering emulsion was prepared using protein nanoparticles as emulsifier by scanning electron microscopy, particle size and surface hydrophobicity changes before and after specific heat induction. The particle size, antioxidant capacity（DPPH radical scavenging rate）, β-carotene retention rate, free fatty acid release rate and bioaccessibility of β-carotene Wild-NPPEs, α-lack-NPPEs, α′-lack-NPPEs and（α+α′）-lack-NPPEs were determined to explore the effect of α and α′ subunits on embedding β-carotene. The results showed that: Protein nanoparticles with different subunits can be prepared by heat induction. α′ subunits have effects on the stability of β-carotene Pickering emulsion. After 30 days of storage at 4 ℃ or 25 ℃, the final retention rate of β-carotene of α′-lack-NPPEs was more than 70%, and the antioxidant activity was the highest. Through in vitro simulated gastrointestinal digestion test, the interface area of α′-lack-NPPEs emulsion droplets was relatively large. Combined with the free fatty acid release rate, it was found that with the decrease of polymerization degree, the surface area of oil droplets increases, the hydrolysis rate increases, and the retention content of β-carotene in micellar phase increases, thus increasing its bioaccessibility. In conclusion, α′-lack-NPs was more suitable for preparing stable β-carotene Pickering emulsion.