Amphoteric emulsifiers are a special class of emulsifying agents containing both positive and negative charge groups within the same molecule. Their molecular structure typically combines anionic groups such as carboxylate or sulfonate with cationic groups like amino or quaternary ammonium groups. This unique composition enables intelligent charge characteristics that vary with pH environments: displaying cationic properties under acidic conditions, anionic properties in alkaline media, and zwitterionic structure near the isoelectric point. These emulsifiers exhibit extremely low skin irritation, excellent biocompatibility, and remarkable hard water resistance, capable of synergistic blending with all emulsifier types while enhancing interfacial film strength. Representative varieties include betaines, amino acid-based types, and lecithin derivatives, widely used in baby care products, premium cosmetics, pharmaceutical emulsions, and specialized industrial emulsification systems. Their mild characteristics and pH responsiveness make them ideal for high-safety formulations and intelligent emulsion systems.