The ecological environment influences the accumulation of chemical components and the formation of regional characteristics of tobacco leaf. Soluble sugars and organic acid play an important role in smoke quality of tobacco products. However, few reports about the effects of light intensity on soluble sugars and organic acid have been published. To study the effects of sunlight on the accumulation of soluble sugars and organic acid, tobacco grown in the field was shaded with sunshade net, and sampled at the harvest time and post-cured period. The samples were then measured for soluble sugars and organic acid. The results showed that except for sucrose in leaf at harvest, reduced light led to lower glucose, fructose and sucrose level in leaves at harvest or post-cured. As for organic acid, reduced light intensity would decrease all the organic acid measured in this study in leaf at harvest. Reduced light intensity led to higher oxalic acid, malic acid and citric acid in flue-cured leaf; while lower light intensity resulted in lower Palmitic acid, linoleic acid, stearic acid, mixture of linolenic acid, and oleic acid in flue-cured leaf. The results from this study shed light on the formation and development of tobacco leaf with regional characteristics and could be used as the references for the chemical compositions of shade-grown tobacco leaf, such as cigar wrapper. (Reprinted with permission)