Abstract: In order to meet the needs of people to supplement the element selenium, in this paper, rice with retained germ was used as raw material to prepare selenium-enriched rice with retained germ by ultrasonic soaking. The optimal process conditions were optimized by single factor experiment, principal component analysis and response surface experiment, and the quality characteristics such as cooking characteristics, texture characteristics, gelatinization characteristics and thermal characteristics of rice with retained germ were studied. The results showed that the optimal process conditions were ultrasonic soaking time 8.25 min, ultrasonic soaking temperature 40 ℃ and ultrasonic power 150 W. Under these conditions, the comprehensive score of selenium-enriched rice with retained germ was 97.31±0.12. The surface pores of rice with retained germ were uniformly formed, the content of immobilized water and free water was increased, the cooking characteristics of rice grains were good, the texture was loose, soft and non-sticky, the taste was smooth, and the nutritional quality was improved.