Abstract: In this text, rice bran protein (RBP) was extracted from rice bran using natural deep eutectic solvents (NADES), as well as the extraction processing of parameters were systemically optimized. RBP was characterized by fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Results showed that, the optimization extraction of RBP parameters were carried out as follows: Proline-glycerol (molar ratio 2:5), 4.7% of water in system, solid-liquid ratio of 9:30 g/g for rice bran to NADES, reaction temperature at 65 ℃ for 3.0 h. The maximum extraction efficiency of RBP was 82.69% under the aforementioned conditions. The new chemical compound in the extraction processing of RBP were not able to be observed in terms of FTIR. The micrograph structure of rice bran was effectively damaged as shown in SEM, which might be a reasonable answer for the better extraction efficiency of RBP in NADES. The results in the present work guided for extraction of plant-based proteins with a designed NADES.