Bitter substances， widely distributed and structurally diverse compounds， are of genuine plant origin mostly， few from animals， while others are generated during the processing， aging， or spoilage of food. The bitter substances in plants mainly include polyphenols， alkaloids， saponins， inorganic salts， amino acids and polypeptides. Bitter substances are perceived by taste buds， and their stimulations are converted into taste signals through bitter taste receptors and transmitted to the brain center to create a bitter sensation. Bitterness is unacceptable for most people， but it plays a key role in taste reconciliation and physiological regulation. Which can be combined with other tastes to enrich the flavor of food. At low intensity， mixtures of bitter with sweet or sour compounds enhanced each other， while umami and salty taste inhibit bitterness； at medium and high intensity， bitterness was suppressed by sweet， sour， umami and salty taste. Bitter substances have health benefits， can be widely used as additives in the food industry. Such as polyphenol， an antioxidant and antimicrobial， can be used for food preservation. Peptides can be added to health food and nutrition supplement to enhance the absorption of nutrition.