•Rice protein (RP) binding with anthocyanins (ACN) caused fluorescence quenching.•The formation of RP-ACN complexes was driven by the hydrophobic and hydrogen bonds.•The secondary structure of RP was altered by complexation with ACN.•A rod-like structure with a high aspect ratio was observed in RP-ACN at pH3.•The functionality and antioxidant ability of RP increased by binding with ACN. This study investigated the functional properties and structural changes associated with the complexation of rice protein (RP) with anthocyanins (ACN). Furthermore, fractions (i.e., albumin, globulin, prolamin and glutelin) isolated from RP complexed with anthocyanins were examined. The interactions with ACN altered the structure of RP, leading to an increase in the β-sheet and spectral shift of the amide Ⅱ band. Additionally, fluorescence spectroscopy suggested that the hydrophobic and hydrogen bonds were the dominant forces in the formation of RP-ACN complexes. It was interesting to find that the RP-ACN particles exhibited the best functional properties at pH 3, likely due to the specific conformational changes upon interaction. In addition, the combination of RP and ACN increased the antioxidant ability of RP. Overall, this research suggested that RP-ACN particles at pH 3 can be designed to form and stabilize mesostructures such as foams and emulsion, which can lead to health benefits.