β-Carotene is used in food industry as a precursor of vitamin A with potent antioxidant activity through singlet oxygen quenching and deactivation of free radicals. Nevertheless, their utilization as nutraceutical ingredients in food industry is currently limited because of their poor watersolubility, high melting point, chemical instability and low bioavailability. Emulsionbased systems are often a better choice for delivering bioactive lipids such as β-carotene into functional foods since the emulsion increases bioavailability. The physical properties of β-carotene emulsions were characterized, which were stabilized by α-lactalbumin (α-LA) at different pH values with (-)-epigallocatechin-3-gallate (EGCG) as antioxidant. The particle size, zetapotential, encapsulation rate, stability index and interfacial protein of the emulsions were measured. EGCG addition had no effect on particle size, zetapotential and encapsulation rate of the emulsions, however, the addition of EGCG significantly influenced the physical stability of the emulsions. When the addition of EGCG was higher than 02% in the emulsions at pH value of 2.0, the physical stability was decreased with the increase of addition. The stability of emulsions at pH value of 7.0 was improved by the addition of EGCG in the range of 0.0025%~0.0200%, however, the stability of the emulsions was decreased when the EGCG addition was within 0.02%~0.10%. When the addition of EGCG was higher than 0.10%, the emulsions were separated into two phases quickly. In the mechanism study, the presence of EGCG changed the size and turbidity in α-LA solution when the addition was above 0.05%. Isothermal titration calorimetry (ITC) analysis implied that EGCG can interact with α-LA, with about five EGCG molecules integrated with one α-LA molecule. β-carotene emulsions destabilized by EGCG addition (greater than 0.10%) may due to the interaction between EGCG and α-LA.