Abstract: The paper studied the effect of spraying GA in different concentrations and different growth stages on the tobacco leaf growth and tobacco quality in the west droughty region of Henan Province by field examination. The results showed that: spraying GA with appropriate concentration on topping stage could enlarge flue-cured tobacco leaf area of upper and total leaves, especially the treatment of spraying GA with 20mg/kg could optimize the factors of yield composition, and lower the thickness of upper tobacco leaves，nicotine and free nicotine content. Thus, the quality of tobacco leaf and usability of upper tobacco leaf are improved. Meanwhile, it could stabilize nitrite content and harmonize chemical constituents of middle and upper tobacco leaf.