Abstract: This paper summarized the effects of the starch degradation on the quality of flue-cured tobacco and the biochemical processes of the starch degradation of the flue-cured tobacco during flue-curing process as well as the factors affecting the degree and rate of the starch degradation. During flue-curing, both the degree and products of the starch degradation affect the quality of flue-cured tobacco, the starch degradation of the flue-cured tobacco is accomplished mainly by two biochemical pathways, i.e. hydrolysis and phosphorolysis under the catalysis of multiple enzymes. The internal factors influencing the degradation of starch in tobacco leaves included the characteristic properties of tobacco starch, the degree of maturity and the microorganisms of the tobacco leaves and so on. The main external factors were the flue-curing equipments and their parameters, the artificially additive enzymes, microorganism preparations and so forth. This paper could provide a reference for the optimization of the flue-curing technology and the formulation of measures accelerating the starch degradation of the flue-cured tobacco.