The quality of crops attracts the attention of many scholars, and tobacco crops are no exception. Tobacco produced in the Fujian and Yunnan ecological regions is distinguished by its delicate fragrance, while tobacco produced in Henan is famous for its strong aroma. Research has shown that meteorological factors cause these differences, although evaluating how the meteorological conditions of any ecological particular region influence the flavor of tobacco has proved difficult. However, use of the stable carbon isotope technique, which has been widely used in ecological studies, provides a possible approach for solving the above problem. Many studies have demonstrated that the amount of δ¹³C (stable carbon isotope composition) found in plants is influenced by environmental conditions, such as temperature, moisture, illumination, and so on. In addition, δ¹³C has been closely connected with various physiological characteristics. Therefore, the amount of δ¹³C found in plants could be a link between environmental conditions in a region and the resulting physiological characteristics of individual plants. This paper investigates the distribution of δ¹³C in the ecological regions of Henan, Fujian and Yunnan provinces, China. We also wanted to know if the amount of δ¹³C found in plants could be used to evaluate the effect of the environment on the quality of tobacco.The Tobacco cultivar K326 was planted in three different ecological regions; one test site was located in each of three provinces, Henan, Fujian and Yunnan. During the tobacco growing season, the Fujian and Yunnan test zones have adequate precipitation and low average temperatures (20.8 ℃ and 22.8 ℃, respectively) in contrast to the Henan test zone, which has sparse precipitation and high temperatures (25.7 ℃) that are not as favorable for growing tobacco. Mature leaves from different leaf positions (from ground to top, selecting the 7^th, 10^th,13^th and 16^th leaf from tobacco plants) were collected as test samples; then, δ¹³C, total organic carbon, total nitrogen and LMA (leaf mass per area) were determined. The results suggested that the δ¹³C levels in both Yunnan and Fujian tobacco increased with leaf position. The δ¹³C of Henan tobacco did not exhibit this trend. The δ¹³C in samples from the Henan test zone ranged between -27.3 ‰ and -31.2 ‰, averaging -29.7 ‰. The δ¹³C in samples from the Fujian and Yunnan test zones had similar levels and were between -24.0 ‰ and -27.1 ‰ and between -24.6 ‰ and -28.6 ‰, respectively, averaging -26.3 ‰ and -25.6 ‰, respectively. Henan tobacco had the highest leaf total nitrogen content, but the total organic carbon content, C/N ratio and LMA were lowest in Henan tobacco. However, the data for each measurement of Fujian's and Yunnan's tobacco leaves were quite similar. Additionally, while Fujian and Yunnan tobacco obviously had similar physiological characteristics, they were quite different from Henan tobacco. The correlation analysis suggested that δ¹³C was negatively correlated with total nitrogen, and positively correlated with the C/N ratio and LMA. In conclusion, based on the relationships of δ¹³C with total organic carbon and total nitrogen, δ¹³C could provide a link for biochemical coupling between nitrogen and carbon metabolism. Plastid segments, nicotine, protein and neutral aroma constituents, which are known to be decisive factors that determine tobacco quality, were all allied to nitrogen and carbon metabolism. That is, the results verified our hypothesis that δ¹³C could be a link between meteorological factors and tobacco quality. In summarizing the above arguments, we believe that δ¹³C can be used to evaluate the effects of environmental variables on tobacco quality.