Abstract: To investigate the effect of chlorogenic acid quinone (CGAQ) concentration on the structural and functional properties of ovalbumin-chlorogenic acid (OVA-CGA) covalent conjugates, which were prepared by bulk electrolysis at OVA free sulfhydryl groups to CGAQ molar ratios of 2:1, 1:1, and 1:2. The free sulfhydryl and amino group contents, CGA grafting rate, secondary and tertiary structural changes, antioxidant activity, solubility, foam stability, and emulsifying activity of OVA and OVA-CGA conjugates were systematically analyzed. The results indicated that with increasing CGAQ concentration, the contents of free sulfhydryl and amino groups in OVA significantly decreased from 7.26±0.14 μmol/g and 180.26±3.59 μmol/g to 1.65±0.14 μmol/g and 159.32±6.63 μmol/g, respectively, with the CGA grafting rate ranging from 21.31% to 31.02%. CGAQ modification did not significantly alter the secondary structure of OVA but induced unfolding of the protein's tertiary structure. Additionally, CGAQ modification significantly enhanced the antioxidant activity of OVA, with DPPH and ABTS⁺ radical scavenging capacities increasing by 6.99-fold and 1.31-fold, respectively. Furthermore, the solubility, foam stability, and emulsifying activity notably improved to 1.38±0.01 mg BSA/mL, 76.53%±1.31%, and 38.46±0.55 m²/g, respectively. The findings of this study provide theoretical guidance for the modulation of functional properties of ovalbumin and the development of functional foods.