Abstract: Carbohydrates are the most abundant aroma precursors in tobacco, mainly existing in the forms of monosaccharides, oligosaccharides, polysaccharides, and carbohydrate derivatives such as glycosides, sugar esters, and Amadori compounds. These carbohydrate compounds could play a key role in the formation of tobacco aroma via Maillard reaction, sugar cracking reaction, caramelization reaction, direct migration into smoke, and many other ways. We reviewed the existing forms of sugar aroma precursor substances in tobacco, summarized the ways in which those sugar aroma precursors affect tobacco aroma quality, and discussed the specific roles of different sugar forms in the formation of aroma quality. The paper would provide information for the improvement of the aroma quality of tobacco products based on application of carbohydrates.