The study was conducted to understand the effect of zein-gum Arabic (GA) complex coacervates prepared by ultrasound treatment on the encapsulation of resveratrol. Compared with zein, zein-GA complex coacervation largely increased the encapsulation efficiency from 26.19% to 55.85% and it was further increased to 74.2% after sonication. Also, prominent rise in the related loading capacities from 2.79% to 6.01% was noted. The increased particle size by the addition of GA and polydispersity index of the ternary complex was dramatically reduced after ultrasound treatment; the absolute values of zeta potential were increased. The hydrogen bonds, electrostatic interactions and hydrophobic effects were the main driving forces for the formation of the ternary complex particles. Ultrasound treatment strengthened the hydrogen bonding and electrostatic interactions, resulting in the formation of compact and homogeneous composite nanoparticles with smaller particle size, which was further confirmed by scanning electron microscope and atomic force microscope. These findings reveal the mechanism of ultrasound enhancing the zein-GA complex coacervation to load resveratrol, and demonstrate its promising effect in modifying protein-polysaccharide complex coacervation as a delivery carrier in the functional food and beverage industry.