The starch contents of flue-cured tobacco harvested in different mature stages (unripe, mature, ripe and over-ripe) were studied in Baofeng, Henan Province. The results showed that: 1) the starch content in fresh leaves increased gradually from unripe to ripe stages, the highest was in the ripe stage, which was 34.67% in cutters and 35.21% in upper leaves, respectively. The starch contents in cutters and upper leaves reduced in over-ripe stage, which were 28.12% and 25.66%, respectively; 2) for tobacco leaves harvested in ripe stage and cured with the three-phase flue-curing method, starch content was lower (5.8%), reducing sugar content was suitable, chemical composition was harmonious, and smoking quality was the best.