In order to improve the stability of loquat flower polyphenols， bovine serum albumin (BSA) and ι-carrageenan were used as wall materials to prepare loquat flower polyphenols nanoparticles by heat treatment. Single factor test and response surface methodology were employed to optimize the preparation process based on the embedding rate of polyphenols. The characteristics of nanoparticles prepared under the optimal preparation process were studied. The results showed that both polyphenol content and DPPH· scavenging activity of ethyl acetate extract of loquat flower alcohol extract were higher than that of other organic solvent extract， and it was used as core material. The optimal preparation process was as follows: the pH of PBS was 6.6， the mass ratio of ι-carrageenan to BSA was 4 ∶ 15， the mass ratio of BSA to core was 15 ∶ 1， the mass concentration of BSA was 1 mg/mL， the temperature of heat treatment was 80 ℃， the embedding rate of polyphenols under this condition was (82.12±0.48)%. The average particle size of polyphenol nanoparticles was (126.0±5.38) nm， the polymer dispersity index (PDI) was 0.43±0.02， the Zeta potential was (-31.1±0.42) mV. Analysis of scanning electron microscope showed that the particles were spherical. The DPPH· scavenging activity of loquat flower polyphenols could be preserved better by embedding treatment， and the stability was stronger.