2,3-butanedione,also known as diacetyl,is a chemical ingredient with butter-like flavor and also naturally exist in butter and fermented beverages. As a synthetic flavor additive,2,3-butanedione is widely used in the production of various foods,such as butter flavored microwave popcorn,chocolate,candy,and baked goods. Recent studies have shown that 2,3-butanedione is correlated with lung disease bronchiolitis obliterans and the over production of reactive oxygen species. The toxicity of 2,3-butanedione in foods has recently attracted the attention not only by consumers but also by regulatory agencies. In this paper,the research advances in the formation mechanism and the quantitative determination of 2,3-butanedione in foods were summarized.