Abstract: To study the effects of air-curing time on flue-cured tobacco quality, air-curing of 24, 48, 72, 96 hours were carried out before flue-curing and compared with curing directly after harvest. Changes of the tobacco curing process, energy and economic traits, appearance quality, chemical composition and smoking quality of cured tobacco leaves were analyzed. The results showed that with air-curing, curing time of flue-cured tobacco could be reduced and so was energy consumption. Improved quality of tobacco leaf appearance, economic traits, chemical composition and smoking quality were also observed. However, with the extension of air-curing time tobacco quality increased firstly and then declined. After comprehensive comparison of flue-cured tobacco quality the best air-curing time was 48 h, which could reduce the curing barn yellowing time within 20 h, save 15% of the energy consumption, with improved appearance quality, 5% higher proportion of superior and middle class leaves, and coordinated chemical composition.