Arbutin is a phenolic glycoside compound naturally found in plants such as bearberry, bilberry, and blueberry. Its molecular structure consists of hydroxyphenol and glucose bound together by a glycosidic bond. As a water-soluble active ingredient, arbutin can mildly inhibit tyrosinase activity, thereby reducing melanin production and achieving whitening, spot-lightening, and even skin tone. Compared to direct use of hydroxyphenol, glycosylated arbutin is less irritating and more suitable for daily skin care. It can be obtained through natural plant extraction or synthesized through chemical or enzymatic methods to ensure high purity and stability. Arbutin is widely used in cosmetics, pharmaceuticals, and health supplements as a safe, gentle, and highly effective whitening active ingredient.